ORM Update - add usingTransaction() to support using explicit transaction

Co-authored-by: robin.bygrave <robin.bygrave@eroad.com>

composites/ebean-clickhouse/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-clickhouse</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-cockroach/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-db2/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-db2</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-h2/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-h2</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-hana/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-hana</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-mariadb/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-mariadb</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-mysql/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-mysql</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-net-postgis/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -14,7 +14,7 @@
 
   <properties>
     <postgis.jdbc.version>2023.1.0</postgis.jdbc.version>
-    <postgres.jdbc.version>42.7.2</postgres.jdbc.version>
+    <postgres.jdbc.version>42.7.11</postgres.jdbc.version>
   </properties>
 
   <dependencies>
@@ -22,13 +22,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -47,19 +47,19 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-net-postgis-types</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>

composites/ebean-nuodb/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-nuodb</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-oracle/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-oracle</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-pgvector/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -22,13 +22,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -47,19 +47,19 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-pgvector-types</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>

composites/ebean-postgis/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -22,13 +22,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -47,19 +47,19 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-postgis-types</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>

composites/ebean-postgres/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-sqlite/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-sqlite</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-sqlserver/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-sqlserver</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean-yugabyte/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -42,13 +42,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/ebean/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
     <relativePath>../..</relativePath>
   </parent>
 
@@ -17,13 +17,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -41,7 +41,7 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-jackson-mapper</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -60,13 +60,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-querybean</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-all</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
   </dependencies>

composites/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
 
   <artifactId>composites</artifactId>

docs/LIBRARY.md

@@ -54,7 +54,8 @@ Ebean is an ORM library for Java and Kotlin focused on relational data access, t
 | `exists()` | Efficient existence checks | `new QCustomer().email.equalTo(email).exists();` |
 | `findOne()` | Unique/single-row retrieval | `new QCustomer().id.equalTo(id).findOne();` |
 | `findList()` | List retrieval | `new QCustomer().findList();` |
-| `asDto(...).findList()` | DTO projection reads | `new QOrder().asDto(OrderSummary.class).findList();` |
+| `asDto(...).findList()` | Flat DTO projection reads | `new QOrder().asDto(OrderSummary.class).findList();` |
+| `mapTo(...).findList()` | Nested DTO graph projection reads | `new QCustomer().mapTo(CustomerDto.class).findList();` |
 
 ### Entity mapping and lifecycle annotations
 
@@ -188,6 +189,7 @@ database.save(customer);
 | Model entity beans correctly | [entity-bean-creation.md](guides/entity-bean-creation.md) |
 | Use Lombok safely with entities | [lombok-with-ebean-entity-beans.md](guides/lombok-with-ebean-entity-beans.md) |
 | Write type-safe query bean queries | [writing-ebean-query-beans.md](guides/writing-ebean-query-beans.md) |
+| Map nested entity graphs to DTO graphs | [mapping-entity-graphs-to-dtos.md](guides/mapping-entity-graphs-to-dtos.md) |
 | Persist changes and manage transactions | [persisting-and-transactions-with-ebean.md](guides/persisting-and-transactions-with-ebean.md) |
 | Build test entities quickly | [testing-with-testentitybuilder.md](guides/testing-with-testentitybuilder.md) |
 

docs/dto-mapping-design.md

@@ -0,0 +1,990 @@
+# Nested DTO Mapping — API Design
+
+Design spike for the accepted requirements in [dto-mapping-requirements.md](./dto-mapping-requirements.md),
+covering issue #2540. This captures the concrete API shape, annotations, and open-question decisions made
+during design review — before implementation begins.
+
+## Two source-vs-target mapping pipelines
+
+Ebean now has (or will have) two distinct DTO pipelines. It's important callers can tell which one they're
+using:
+
+1. **`asDto(Dto.class)`** (existing) — a `DtoQuery`, executed directly against a flat SQL `ResultSet`.
+   One row -> one DTO, via constructor/setter matching. No nested ToOne/ToMany support, no entity graph
+   involved.
+2. **`mapTo(Dto.class)`** (new) — runs the normal ORM entity query (joins/fetches as usual), producing an
+   *unmodifiable entity graph*, then maps that Java object graph into a DTO graph. Supports nested
+   ToOne/ToMany, identity-aware de-duplication, and derives its own fetch spec from the DTO shape.
+
+## Proposed API
+
+```java
+// Existing flat DtoQuery pipeline — unchanged
+new QUser().valid.eq(true)
+    .select(firstName, lastName)
+    .asDto(UserInfo.class)
+    .findList();
+```
+
+```java
+// NEW: nested DTO graph pipeline
+public class CustomerDto {
+  Long id;
+  String name;
+  AddressDto billingAddress;      // ToOne -> nested DTO, matched by property name "billingAddress"
+  List<ContactDto> contacts;      // ToMany -> nested DTO list, matched by property name "contacts"
+
+  @DtoPath("billingAddress.line1")
+  String billingLine1;            // renamed / flattened path
+}
+
+public class ContactDto {
+  Long id;
+  String firstName;
+  String lastName;
+
+  @DtoRef
+  Long customerId;                // id-only back-reference, avoids re-embedding CustomerDto (cycle)
+}
+
+List<CustomerDto> dtos = new QCustomer()
+    .status.eq(Status.ACTIVE)
+    .mapTo(CustomerDto.class)
+    .findList();
+```
+
+Computed values (e.g. `cityOrUnknown` derived from `coalesce(billingAddress.city, 'Unknown')`) are
+**not** modeled with a `@Formula2` annotation directly on the DTO - that was explored and rejected
+(see "Formula2-on-DTO scope" below). Instead they're modeled as a plain matching field on the DTO,
+sourced from an `@Entity @View` entity that itself carries the `@Formula2` - see "Computed/aggregate
+properties" below for the worked example.
+
+`mapTo(CustomerDto.class)`:
+- Introspects `CustomerDto` (recursively, at codegen time) to derive the `select(...)`/`.fetch(...)` spec
+  automatically from the DTO's declared shape.
+- Forces `setUnmodifiable(true)` under the hood — gives fail-fast + a cheap, non-mutable source graph
+  (satisfies the fail-fast requirement without a separate flag).
+- Runs the query, then runs a mapper over the resulting entity graph, de-duplicating DTO instances by id
+  for repeated nested references (identity-aware, mirrors the source entity graph's own de-duplication).
+
+## Decisions made
+
+### Fetch spec: auto-derived from DTO shape
+
+The DTO's declared structure (fields, nested DTO types, `@DtoPath` overrides) is the single source of truth
+for what gets selected/fetched from the database. Callers do not need to separately maintain a `.fetch(...)`
+spec in parallel with the DTO — this directly addresses the original issue's pain point (DTO and query
+projection drifting out of sync).
+
+### Entry point naming: `mapTo(Dto.class)`
+
+Chosen over `asGraph(...)` / `into(...)` / overloading `findList(Class)`. Reads clearly as "map the
+resulting entity graph to this DTO type" and is unambiguous against the existing `asDto(...)` (flat,
+SQL-row-based) mechanism.
+
+### Cycle handling: codegen-time DAG check + `@DtoRef` escape hatch
+
+Because the fetch spec and mapper are both derived from the *static* DTO type graph (not live object
+traversal), cycle detection is a compile-time/codegen-time concern, not a runtime one. This is stronger
+than the common approach in the ecosystem:
+
+- **MapStruct** does not auto-detect cycles. It offers an opt-in `@Context` "cycle guard" pattern (an
+  identity map of already-mapped source -> target objects) that the developer must wire up manually to
+  avoid infinite recursion mapping bidirectional object graphs.
+- **Blaze-Persistence / QueryDSL / JOOQ record mapping** avoid the problem architecturally: view/projection
+  types are required to be a strict tree; a back-reference is modeled as an id or a much shallower type,
+  never the same full view type again.
+
+Ebean's approach: fail the build at annotation-processing time if a DTO's declared type graph is not a DAG,
+with a clear error message. Provide `@DtoRef` as an explicit escape hatch for intentional back-references
+(e.g. `Contact.customer`) — it maps only the id, not the full nested DTO, breaking the cycle by design
+rather than by runtime guard.
+
+### `@DtoPath` / `@DtoRef`: parallels for readers coming from MapStruct or Blaze-Persistence
+
+Neither annotation is a novel concept - both map onto things MapStruct and Blaze-Persistence users will
+already recognise, which is worth spelling out explicitly so it's easy to "grok fast":
+
+- **`@DtoPath("billingAddress.line1")` is Ebean's equivalent of MapStruct's dot-path `source` flattening**
+  — e.g. `@Mapping(target = "line1", source = "billingAddress.line1")`. MapStruct auto-generates a
+  null-safe chain of getter calls for a dotted `source`; `@DtoPath` does exactly the same thing, just
+  declared on the DTO field itself rather than on a mapper method parameter list. It is also close to
+  Blaze-Persistence's `@Mapping("billingAddress.line1")` on an `@EntityView` attribute, which is a JPQL
+  path expression evaluated the same way — Blaze's placement (directly on the target view property) is
+  actually the closer analogue of the two, since Ebean's `@DtoPath` is likewise placed on the DTO field.
+  The difference from Blaze: `@DtoPath` is restricted to plain getter-chain navigation (no arbitrary JPQL/
+  SQL expression) - see "Formula2-on-DTO scope" below for the boundary and why full expression support is
+  deliberately deferred.
+- **`@DtoRef` has no dedicated equivalent in either tool** - both MapStruct and Blaze would express the
+  same "just the id" mapping as a plain dot-path to `.id` (`@Mapping(source = "customer.id")` / Blaze
+  `@Mapping("customer.id")`), with no special marker for it. What `@DtoRef` adds beyond that shorthand is
+  *intent*: it tells the codegen this property is a deliberate cycle-breaking reference, so (a) it adds
+  just the association's own name (not a dotted `.id` path) to the generated fetch spec's root
+  `select(...)` - reading the FK column directly with no join, and skipped entirely if that same
+  association is already fully fetched by a `NESTED_ONE`/`NESTED_MANY` property elsewhere on the same DTO
+  (see `DtoMapperWriter.fetchGroupChainCalls()`'s `case REF` branch) - and (b) it participates in the
+  codegen-time DAG cycle check above as an explicit "this is fine, don't flag it" signal, rather than
+  requiring a suppression escape hatch bolted on afterwards.
+
+  **Bug found and fixed while building the aggregation worked example below:** the original implementation
+  excluded `REF` properties from the fetch spec *entirely*, on the assumption the id is "already available
+  off an unfetched reference without triggering a fetch/lazy load". That assumption is only true when some
+  *other* property on the same DTO happens to also fetch that association (as was always the case in the
+  existing hand-built examples). Tested directly against a bare `@ManyToOne` with no other fetch of it:
+  accessing `.getCustomer().getId()` in that case triggers a full lazy-reload of the owning row (extra SQL,
+  not free) - and for an aggregation query it's worse, since the property being grouped by must be selected
+  or the query can't group correctly at all. Fixed so `REF` always contributes its association name to the
+  root `select(...)` (deduped against any existing `NESTED_ONE`/`NESTED_MANY` fetch of the same path).
+
+**Bug found and fixed (validation phase, testing against `central-access`): primitive-typed field +
+nullable intermediate hop = unboxing `NullPointerException`.** A multi-hop `@DtoPath` (or `@DtoRef`,
+which is always 2-hop) null-guards each intermediate getter with a ternary, e.g.
+`(source.getOrganisation() == null ? null : source.getOrganisation().getId())`. That ternary's static
+type is always the boxed wrapper (`Long`), since one branch is the `null` literal - fine when the DTO
+field is itself a reference type (`Long organisationId`), but when the DTO field is a **primitive**
+(`long organisationId`), passing that boxed expression to the constructor auto-unboxes it, throwing an
+unhelpful `NullPointerException` at runtime whenever the relation really is `null`. This compiled clean
+and only failed at runtime with real (nullable) production data - exactly the kind of gap a hand-written
+mapper would defensively guard against (e.g. `cEbox.getOrganisation() == null ? 0 : ...getId()`) but
+generated code didn't.
+
+Fixed in the generator: when a multi-hop `SCALAR`/`REF` property's DTO field type is primitive, the
+whole null-guarded chain is now wrapped in a small runtime helper (`io.ebean.DtoMapperSupport`) that
+resolves it safely:
+- **Default** (`@DtoPath` with no `failOnNull`, or any `@DtoRef`): silently defaults to the primitive's
+  zero-equivalent value (`0`/`false`/etc.) - matches the old hand-written-mapper convention.
+- **`@DtoPath(failOnNull = true)`**: throws a clear `IllegalStateException` naming the offending property
+  path instead, for callers who'd rather fail fast than silently mask a null they don't expect.
+
+`@DtoRef` has no `failOnNull` attribute (it has no other attributes at all) - it always uses the
+default (silent zero) behaviour. See `PrimitiveNullPathDto`/`PrimitiveNullPathFailOnNullDto` /
+`TestPrimitiveNullPath` for regression coverage.
+
+### Read-only entity memory overhead: `InterceptReadOnly`
+`setUnmodifiable(true)` isn't just a behavioural fail-fast flag - it also swaps the per-bean intercept
+implementation to `InterceptReadOnly`, which is deliberately minimal: just a `boolean[] loaded` (one flag
+per property) and a `boolean frozen`, plus the inherited owner reference and `fullyLoadedBean` flag. Compare
+to `InterceptReadWrite` (the mutable/updatable variant), which additionally carries a `ReentrantLock`, four
+transient collaborator references (`NodeUsageCollector`, `PersistenceContext`, `BeanLoader`,
+`PreGetterCallback`), a `byte[] flags` array (per-property loaded+changed+dirty+orig-value-set state),
+`Object[] origValues`, `Exception[] loadErrors`, `MutableValueInfo[]`/`MutableValueNext[]`, and several more
+scalar bookkeeping fields. None of that is needed for a bean that will only ever be read, so
+`setUnmodifiable(true)` graphs carry meaningfully less per-instance overhead than normal fetched entities -
+relevant here because `mapTo(Dto.class)` forces `setUnmodifiable(true)` on its underlying query, making the
+*source* graph for a DTO mapping cheaper than the equivalent normal (writable) entity graph would be.
+
+### Ad-hoc computed/formula properties: model as `@Entity @View`/`@Sql`, not ad-hoc SQL-on-DTO
+
+The "fully ad-hoc SQL-on-DTO" stretch goal above (closer to Blaze's arbitrary `@Mapping` expressions) doesn't
+need to be built as a bespoke DTO-annotation-processing feature. Ebean already supports modelling read-only,
+computed, or view-backed data as ordinary entities via `@Entity` + `@View` (backed by a SQL view, e.g. one
+with aggregates/computed columns) or `@Entity` + `@Sql` (backed by arbitrary `RawSql`, no base table). Given
+that, the Blaze-Persistence-style "an entity view attribute backed by an arbitrary SQL expression" need can
+usually be satisfied by:
+
+1. Modelling the computed/derived shape as its own `@Entity @View` (or `@Sql`) "read entity" - the SQL
+   expression/aggregation lives in the view definition, not in a new annotation-processed DTO mechanism.
+   `@View`'s `name()` doesn't have to point at a genuinely separate database view - it can just point at
+   an *existing* table (e.g. `@View(name = "contact")` on a second entity class reading the same table as
+   `Contact`) purely to mark the entity as view-like/read-only, in which case Ebean's DDL generator emits
+   **no new table or view at all** for it - it's just a second lens onto the same physical data.
+2. Mapping *that* entity into a plain DTO using the existing, already-implemented `@DtoMapping` machinery -
+   no ad-hoc-SQL-on-DTO support required, since there's no computed expression left to resolve at the DTO
+   layer at all; it's just another entity-to-DTO mapping.
+3. This read entity benefits from the same `setUnmodifiable(true)`/`InterceptReadOnly` memory efficiency
+   above when used purely as `mapTo(...)` input, so there's no meaningful cost to preferring this over a
+   hypothetical native ad-hoc-SQL-on-DTO feature.
+
+This significantly narrows (and may eliminate) the case for a dedicated ad-hoc-SQL-on-DTO mechanism - it
+remains listed as an open stretch goal below primarily for the case where a computed value's SQL is genuinely
+one-off/DTO-specific and not worth promoting to a standalone `@View`/`@Sql` entity.
+
+**Worked example** (`tests/test-dto-mapping`): `ContactSummary` is `@Entity @View(name = "contact")` (no new
+DDL - reads the same table as `Contact`) with `@Formula2("concat(firstName, ' ', lastName)")` computing
+`fullName`; `ContactSummaryDto` is a plain two-field DTO; `@DtoMapping(source = ContactSummary.class, target
+= ContactSummaryDto.class)` generates `ContactSummaryDtoMapper` exactly like any other entity→DTO pair - the
+formula property is just selected like any other field (`select("id,fullName")` in the generated
+`fetchGroup()`). See `TestContactSummaryDtoMapping`.
+
+### Aggregate/group-by computed properties: `@Sum`/`@Aggregation` as `@Entity @View`, same pattern
+
+Ebean's `@Sum` (shorthand for `@Aggregation("sum($1)")`) and `@Aggregation("count(...)"/"sum(...)"/"avg(...)"/
+"min(...)"/"max(...)")` are the group-by parallel to the formula pattern above - the same `@Entity @View`
+approach applies, just with an implicit `GROUP BY` instead of a per-row computed column. Ebean auto-derives
+the `GROUP BY` clause from whichever non-aggregate properties end up in the query's `select()`/`fetch()` - so
+a second `@Entity @View(name = <same base table>)` entity with one or more `@Sum`/`@Aggregation` properties
+plus a `@ManyToOne` grouping key becomes a per-parent rollup, with **no new table/view and no explicit
+`.groupBy()` call required**. This is Ebean's parallel to Blaze-Persistence entity view correlated aggregate
+mappings, e.g. `@Mapping("SIZE(contacts)")` / `@Mapping("SUM(contacts.engagementScore)")` on an `@EntityView`.
+
+**Nuance found while building the worked example, and since fixed: `@DtoRef` originally didn't fit the
+grouping key.** `@DtoRef` was originally excluded from the generated `select()`/`fetch()` spec entirely, on
+the premise that the id is already available off an unfetched reference for an ordinary entity graph. That
+premise doesn't hold for an aggregation query: the `@ManyToOne` *is* the property being grouped by, so if
+it's never selected, the query has nothing to group by. It turned out the premise didn't fully hold for
+ordinary entity graphs either - see the `@DtoRef` bug writeup above. Fixed so `@DtoRef` now adds the
+association's own name to the root `select(...)` (reading the FK column directly, no join) - which both
+supplies the grouping key here and fixes the general-case gap.
+
+**Worked example** (`tests/test-dto-mapping`): `ContactStats` is `@Entity @View(name = "contact")` (no new
+DDL - reads the same table as `Contact`/`ContactSummary`) with `@Aggregation("count(id)") contactCount` and
+`@Sum Integer engagementScore` (a new nullable field added to `Contact` purely to have something to sum),
+grouped by its `@ManyToOne customer`. `ContactStatsDto` is a flat 3-field DTO (`customerId`, `contactCount`,
+`engagementScore`), with `customerId` mapped via plain `@DtoRef`. The generated `ContactStatsDtoMapper`:
+
+```java
+this.fetchGroup = FetchGroup.of(ContactStats.class)
+  .select("customer,contactCount,engagementScore")
+  .build();
+...
+// skip DtoMapContext, only ever a top-level mapping
+return new ContactStatsDto(
+  (source.getCustomer() == null ? null : source.getCustomer().getId()),
+  source.getContactCount(),
+  source.getEngagementScore());
+```
+
+confirmed (via `LoggedSql`) to produce `select t0.customer_id, count(t0.id), sum(t0.engagement_score) from
+contact t0 ... group by t0.customer_id` - **no join**, one row per customer, correctly summed and counted.
+See `TestContactStatsDtoMapping`.
+
+### Formula2-on-DTO scope (v1): existing entity formulas only
+
+`@Formula2` on a DTO property in v1 only pulls in a formula **already declared on the source entity** (or
+a reachable associated entity) — it does not support fully ad-hoc SQL declared directly on the DTO with no
+matching entity property. Fully ad-hoc SQL-on-DTO (closer to Blaze's arbitrary `@Mapping` expressions) is a
+separate, larger stretch goal to revisit once the core graph-mapping mechanism is proven.
+
+**Attempted and rejected for v1.** A narrower version was implemented (`@Formula2(value)` resolved exactly
+like `@DtoPath` - a dot-path getter chain - plus a codegen-time validation that the resolved entity property
+is itself `@Formula2`/`@Formula`-annotated) but was rejected: for the common case (a DTO field with the same
+name as the entity's formula property) it generated **identical code to a plain unannotated field** - the
+only difference was the validation, which wasn't judged enough distinct value to justify a new annotation
+surface. Not implemented. The only way `@Formula2`-on-DTO would add real value is the full ad-hoc-SQL
+capability described above, which remains an open stretch goal.
+
+### Mapper implementation strategy: codegen, not reflection (native-image constraint)
+
+Native-image support is a core Ebean requirement, so the entity-graph -> DTO-graph mapper must not rely on
+runtime reflection or `MethodHandles`. This ruled out an initial reflection-based spike:
+
+- Ebean's existing flat `DtoQuery` (`DtoMetaConstructor`) already uses `MethodHandles` via
+  `Lookups.getLookup()`, but there is no `reflect-config.json` / native-image reachability metadata shipped
+  for it anywhere in the repo. That existing approach is not a clean precedent to copy for a bigger,
+  native-image-first feature.
+- Instead, the approach mirrors `querybean-generator`, which already generates real `.java` source for
+  `Q*` query bean types (not reflection) — consistent with the wider avaje-ecosystem convention
+  (avaje-inject / avaje-jsonb are explicitly reflection-free via compile-time codegen).
+
+**Implementation sequencing:** hand-write the mapper in the exact shape the annotation processor will
+eventually generate (plain Java, direct getter/constructor/setter calls, zero reflection) for one concrete
+example first, to validate the mapping algorithm and API shape quickly without ever introducing throwaway
+reflective code. That hand-written mapper then becomes the target/acceptance-test shape for the
+`querybean-generator` annotation processor that automates producing it.
+
+### Codegen target: Java first
+
+The mapper generation (requirement r2) targets `querybean-generator` (the existing APT module that already
+generates `Q*` query beans, reusing its `PropertyMeta` / `ProcessingContext` machinery). Kotlin parity via
+`kotlin-querybean-generator` is deferred to a later phase — not blocking initial delivery.
+
+### Mapper composition: one mapper per entity/DTO pair, generic `DtoMapper<SOURCE, TARGET>` interface
+
+Rather than one large mapper inlining every nested DTO type, each entity/DTO pair gets its own small
+mapper class - mirroring MapStruct's per-type mapper generation. All mappers implement a shared generic
+interface (prototyped as `org.tests.dtomapping.DtoMapper<SOURCE, TARGET>` in the spike, expected to move to
+`io.ebean` as a public type once solidified):
+
+```java
+public interface DtoMapper<SOURCE, TARGET> {
+  TARGET map(SOURCE source);
+  default List<TARGET> mapList(List<SOURCE> source) { ... }
+}
+```
+
+A parent mapper composes nested mappers via **constructor injection**, not a static singleton:
+
+```java
+public final class CustomerDtoMapper implements DtoMapper<Customer, CustomerDto> {
+  private final DtoMapper<Address, AddressDto> addressMapper;
+
+  public CustomerDtoMapper() {
+    this(new AddressDtoMapper());
+  }
+
+  public CustomerDtoMapper(DtoMapper<Address, AddressDto> addressMapper) {
+    this.addressMapper = addressMapper;
+  }
+
+  @Override
+  public CustomerDto map(Customer source) {
+    if (source == null) return null;
+    return new CustomerDto(source.getId(), source.getName(), addressMapper.map(source.getBillingAddress()));
+  }
+}
+```
+
+Rationale:
+- **Composability & reuse** - the same nested DTO type (e.g. `AddressDto`) used from multiple parent DTOs
+  reuses one generated mapper class rather than duplicating inline mapping logic.
+- **Constructor injection over static state** - avoids a global mutable singleton; a no-arg constructor
+  gives the common case (default nested mapper), while an overload accepting the nested mapper explicitly
+  allows substitution (tests, customization) without touching global state.
+- **Codegen-friendly** - this shape generates naturally: one top-level mapper class per DTO type, each
+  constructor-injecting the mappers for any nested DTO types it references.
+
+## ToMany collections and identity de-duplication (dto-spike-tomany-identity)
+
+Extending the spike (`ebean-test/src/test/java/org/tests/dtomapping/`) to a `Customer` with a
+`List<Contact> contacts` ToMany, where each `Contact` has a `customer` back-reference, surfaced
+two things worth recording.
+
+### The `DtoMapper` interface threads a shared context
+
+`DtoMapper<SOURCE, TARGET>` was extended so that mapping is always done against a `DtoMapContext`:
+
+```java
+public interface DtoMapper<SOURCE, TARGET> {
+  TARGET map(SOURCE source, DtoMapContext context);
+
+  default TARGET map(SOURCE source) {
+    return map(source, new DtoMapContext());
+  }
+
+  default List<TARGET> mapList(List<SOURCE> source, DtoMapContext context) { ... }
+
+  default List<TARGET> mapList(List<SOURCE> source) {
+    return mapList(source, new DtoMapContext());
+  }
+}
+```
+
+`DtoMapContext` is an identity-keyed cache of already-mapped source -> target instances, created
+once per top-level `mapList(...)`/`map(...)` call and threaded through every nested `map(...)`
+call. This lets repeated references to the *same* source entity instance - which Ebean's own
+persistence context already de-duplicates within one query (`contact.getCustomer() == customer`
+for the enclosing `Customer`, confirmed by an existing test) - map to the *same* target DTO
+instance, rather than each producing an equal-but-distinct copy. This is what makes the mapped
+DTO output "graph shaped" rather than "tree of copies shaped", and is required for r1/r3.
+
+### Bug found and fixed: the cache must be partitioned by target type, not just source identity
+
+The first cut of `DtoMapContext` was a single `IdentityHashMap<Object, Object>` keyed only by the
+source instance. This breaks as soon as the *same* source instance legitimately needs to map to
+*two different target types* within one graph - which happens immediately with a back-reference:
+
+- The top-level `CustomerDtoMapper` maps a `Customer` -> full `CustomerDto`.
+- The nested `ContactDtoMapper`, mapping `contact.getCustomer()` (the *same* `Customer` instance,
+  by identity), maps it -> shallow `CustomerRefDto` (the `@DtoRef`-style escape hatch that avoids
+  the `Customer -> Contact -> Customer` cycle).
+
+With a single un-partitioned identity map, whichever mapper runs first "wins" the cache slot for
+that `Customer` instance, and the other mapper incorrectly receives the wrong-typed cached result
+(a `ClassCastException` at best, silently wrong data at worst). This was caught by a failing test
+during the spike and fixed by partitioning the cache per target type:
+
+```java
+public final class DtoMapContext {
+  private final Map<Class<?>, Map<Object, Object>> mappedByType = new HashMap<>();
+
+  public <S, T> T computeIfAbsent(Class<T> targetType, S source, Function<S, T> mappingFunction) {
+    Map<Object, Object> mapped = mappedByType.computeIfAbsent(targetType, t -> new IdentityHashMap<>());
+    // ... existing/create/put ...
+  }
+}
+```
+
+Each generated mapper passes its own target DTO `Class` as the first argument, so `Customer ->
+CustomerDto` and `Customer -> CustomerRefDto` are cached independently even though the key
+(`Customer` instance) is identical. **This is an implementation detail the codegen must get
+right** - worth flagging explicitly when `dto-codegen-mapper` starts, since it's easy to
+regress if the generator is written from scratch without this test coverage in front of it.
+
+### Codegen optimization: skip the `DtoMapContext` cache for types that are never nested elsewhere
+
+`DtoMapContext.computeIfAbsent` only ever produces a cache *hit* when the exact same source
+instance is presented to `map()` more than once within one top-level call - which can only happen
+when the target type is reachable via more than one path in the graph, i.e. it's used as a
+`NESTED_ONE`/`NESTED_MANY` property by some *other* `@DtoMapping` pair (e.g. `CustomerRefDto`
+reached from many `Contact`s via a shared `Customer`, or `AddressDto` shared as `billingAddress`
+across customers). A type that's only ever a top-level `mapTo(...)`/`mapList(...)` entry point can
+never receive the same source instance twice within one call - Ebean's own query engine already
+de-duplicates root entity instances - so the cache lookup/insert there is pure overhead with a
+guaranteed-never-hit `IdentityHashMap`.
+
+Since all `@DtoMapping` pairs are resolved together at codegen time (`DtoMappingReader.
+resolveAndValidate()`), it's straightforward to compute this: after cycle exclusion, walk every
+surviving `DtoBeanMeta`'s properties and mark any `nested()` target as `nestedElsewhere()`. The
+generated `map()` method then branches per mapper:
+
+```java
+// CustomerDto - never nested by another mapper, only a mapTo()/mapList() entry point
+public CustomerDto map(Customer source, DtoMapContext context) {
+  if (source == null) return null;
+  // DtoMapContext for nested mappers only
+  return new CustomerDto(source.getId(), source.getName(),
+    billingAddressMapper.map(source.getBillingAddress(), context),
+    contactsMapper.mapList(source.getContacts(), context));
+}
+
+// AddressDto - nested under CustomerDto.billingAddress, so may be shared across customers
+public AddressDto map(Address source, DtoMapContext context) {
+  if (source == null) return null;
+  // dedup using DtoMapContext, same Address instance can be reached via more than one path in the graph
+  return context.computeIfAbsent(AddressDto.class, source, s -> new AddressDto(
+    s.getId(), s.getLine1(), s.getCity()));
+}
+
+// ContactSummaryDto - flat, top-level only, no nested children at all
+public ContactSummaryDto map(ContactSummary source, DtoMapContext context) {
+  if (source == null) return null;
+  // skip DtoMapContext, only ever a top-level mapping
+  return new ContactSummaryDto(source.getId(), source.getFullName());
+}
+```
+
+Deliberately terse, single-line comments - just enough for a developer skimming generated code (e.g.
+per the earlier `@Formula2`-on-DTO worked example) to know at a glance *why* a given mapper does or
+doesn't use the cache, without spelling out the full reachability argument inline every time (that
+lives here in the design doc instead). Note `CustomerDto`'s own construction skips the cache even
+though it *has* nested children - `context` is still threaded down to `billingAddressMapper`/
+`contactsMapper` since those target types (`AddressDto`, `ContactDto`) *are* nested elsewhere and
+still need the identity cache for themselves - hence the distinct "for nested mappers only" wording
+from the "only ever a top-level mapping" case (`ContactSummaryDto`), which has no children to thread
+a context to at all.
+
+### Fetching a ToOne back-reference used only for its FK/id needs the FK property fetched too
+
+Confirmed (via a first-cut test failure) that if a ToMany's element type has a ToOne back to its
+parent (e.g. `Contact.customer`), that FK property must itself be included in the fetch
+(`.fetch("contacts", "id,firstName,lastName,customer")`) even when the mapper only reads the id
+off the reference. Omitting it throws `LazyInitialisationException: Property not loaded:
+customer` on the `getCustomer()` call itself (not merely on a property access on the returned
+reference) - i.e. the earlier "ToOne reference access alone doesn't lazy load" finding
+(dto-validate-fetch-pagination) only holds once the ToOne/FK property is itself part of the
+fetch/select spec. This reinforces r6 (auto-deriving the fetch spec from DTO shape): the codegen
+must include a ToOne property in the fetch spec whenever a DTO needing it (even just its id) is
+reachable through a ToMany, not just at the top level.
+
+### Test coverage added
+
+- `TestCustomerDtoGraphMapping` extended to cover `contacts` ToMany mapping and to assert that
+  sibling `ContactDto`s under the same customer share the identical `CustomerRefDto` instance.
+- `TestContactDtoGraphMapping` (new) - standalone `ContactDtoMapper` test focused specifically on
+  the identity de-dup guarantee and null-source handling.
+
+## Codegen foundation: avaje-prisms adopted in querybean-generator (dto-codegen-mapper, step 1)
+
+Before writing the DTO-mapper annotation-processing logic itself, adopted `avaje-prisms`
+(`io.avaje:avaje-prisms`) in `querybean-generator` as the mechanism for reading the new
+`@DtoPath`/`@DtoRef` annotations at APT time, replacing what would otherwise be more hand-rolled
+`AnnotationMirror` walking (the existing pattern in `FindDbName.java`/`ReadModuleInfo.java`,
+left as-is/unmigrated - only the *new* annotations use prisms).
+
+This mirrors the proven pattern already used in two sibling projects in the same ecosystem -
+`avaje-inject`'s `inject-generator` and `avaje-jsonb`'s `jsonb-generator` - both declare
+`@GeneratePrism(SomeAnnotation.class)` once and get a generated `SomeAnnotationPrism` with
+`isPresent(element)` / `getInstanceOn(element)` / `getOptionalOn(element)` and typed accessors
+for every annotation member (correctly handling `Class`-valued members, avoiding the classic
+`MirroredTypeException` dance).
+
+Key property preserved: `querybean-generator` has **zero runtime/compile dependencies today**
+(confirmed via `mvn dependency:list` returning "none"), matching annotations by FQN string
+constants (`Constants.java`) rather than importing the actual annotation classes - deliberately
+keeping the processor free of any dependency footprint for consumers. Adding `avaje-prisms` (to
+generate the prism wrapper) and `ebean-annotation` (to reference `@DtoPath`/`@DtoRef` as literal
+`Class` values in `@GeneratePrism(...)`) as `optional` dependencies preserves this: `mvn
+dependency:list -DincludeScope=runtime` confirms every one of these (plus their own transitive
+deps: `avaje-prism-core`, `avaje-spi-service`, `avaje-spi-core`) is marked `(optional)`, so none
+of it propagates to a project that depends on `querybean-generator` (whether as a normal
+dependency or via `annotationProcessorPaths`).
+
+New annotations were added to the separate `ebean-annotation` repo (`io.ebean.annotation`
+package, alongside `@Formula2`), not this repo:
+
+```java
+@DtoPath("billingAddress.line1")
+String billingLine1;   // rename/flatten a DTO property from a nested source path
+
+@DtoRef
+Integer customerId;    // id-only back-reference, breaks what would otherwise be a graph cycle
+```
+
+Both use `@Target({FIELD, METHOD})` and `RetentionPolicy.CLASS` - visible to the annotation
+processor (including across module boundaries, since `CLASS` retention survives in the compiled
+`.class` file) but absent from runtime reflection, consistent with DTOs remaining plain,
+framework-free types with no runtime footprint.
+
+Wiring changes in `querybean-generator`:
+- `pom.xml`: added `avaje-prisms` (`optional`, plus `annotationProcessorPaths` entry) and
+  `ebean-annotation` (`optional`) dependencies; removed the previous `-proc:none` compiler arg
+  (which would have suppressed `avaje-prisms`' own processor from running to generate the prism
+  source) - annotation processing is now scoped to exactly `avaje-prisms` via the explicit
+  `annotationProcessorPaths` list, so no other processor is auto-discovered.
+- `module-info.java`: added `requires static io.avaje.prism;` and `requires static
+  io.ebean.annotation;` (`static` = compile-time only, matching the `optional` Maven scope).
+- New `package-info.java` declaring `@GeneratePrism(DtoPath.class)` and
+  `@GeneratePrism(DtoRef.class)`, generating `DtoPathPrism`/`DtoRefPrism` into
+  `target/generated-sources/annotations`.
+
+Verified: full `querybean-generator` build + existing test suite pass unchanged, and a downstream
+full rebuild (`ebean-test` with `-am`) - which exercises the existing Q-bean codegen - also
+passes with no regressions.
+
+### Trigger mechanism: `@DtoMapping(source, target)` on a neutral package-info.java
+
+Considered and rejected: putting a `source`/entity-referencing annotation directly on the DTO
+class itself (e.g. `@Dto(Customer.class)` on `CustomerDto`). Rejected because DTO types are
+often owned/generated elsewhere (e.g. from an OpenAPI spec) and must not be forced to reference
+an internal persistence/entity type - that would leak internal domain types into a
+public-facing/generated DTO module.
+
+Instead, adopted the same pattern `avaje-jsonb` uses for external/foreign types it doesn't own
+(`@Json.Import`): a repeatable annotation declared on a *neutral* holder - a `package-info.java`
+- naming the `source` entity and `target` DTO as a pair:
+
+```java
+@DtoMapping(source = Customer.class, target = CustomerDto.class)
+@DtoMapping(source = Contact.class, target = ContactDto.class)
+package org.example.dto;
+```
+
+`@DtoMapping` (new, in `ebean-annotation`) is `@Target({PACKAGE, MODULE})`,
+`@Retention(SOURCE)` (pure codegen trigger, never needed at runtime - unlike `@DtoPath`/
+`@DtoRef` which need `CLASS` retention to remain visible to the DTO field itself),
+`@Repeatable(DtoMapping.List.class)` following Java's own repeatable-annotation idiom. Neither
+the entity nor the DTO needs any annotation of its own.
+
+**Generated mapper package placement** - also modeled directly on `avaje-jsonb`'s handling of
+`@Json.Import` for external types (`AdapterName`/`ProcessingContext.isImported`): defaults to the
+target DTO's own package, *unless* the source or target type belongs to a different Java module
+than the one being processed, in which case the generated mapper is placed in a package derived
+from the processing module's own name instead - avoiding a JPMS "split package" violation that
+would occur from generating source into a package owned by another module. An explicit
+`mapperPackage` attribute is available to override this for edge cases. Same-module (or
+non-modular/unnamed-module) projects are unaffected and just get the mapper alongside the DTO.
+
+### mapTo(Class) dispatch: Class-token API + generated compile-time-safe registry
+
+The original API sketch above (`mapTo(CustomerDto.class)`) predates the native-image/no-reflection
+decision. Rather than switching to an instance-based API (`mapTo(new CustomerDtoMapper())`),
+decided to keep the `Class`-token shape and generate a compile-time-safe registry to resolve it -
+no reflection, no `Class.forName`, just literal `Class` comparisons generated at build time, e.g.:
+
+```java
+<S, D> DtoMapper<S, D> mapperFor(Class<S> sourceType, Class<D> targetType) {
+  if (sourceType == Customer.class && targetType == CustomerDto.class) {
+    return (DtoMapper<S, D>) new CustomerDtoMapper();
+  }
+  if (sourceType == Contact.class && targetType == ContactDto.class) {
+    return (DtoMapper<S, D>) new ContactDtoMapper();
+  }
+  return null;
+}
+```
+
+Dispatch is keyed on the **(source, target) pair**, not target alone - this matches how
+`@DtoMapping(source, target)` pairs are declared, allows the same DTO type to be mapped from more
+than one source entity without ambiguity, and lets `query.mapTo(dtoType)` fail fast with a clear
+`PersistenceException` (rather than an incorrect match) when `query.getBeanType()` doesn't pair
+with the requested DTO.
+
+This mirrors the existing, already-proven `EbeanEntityRegister`/`EntityClassRegister` mechanism
+(`SimpleModuleInfoWriter.java`) that `querybean-generator` already generates per module for entity
+classes - a `List<Class<?>>` built from literal `SomeEntity.class` references, registered via
+`META-INF/services` (`ServiceLoader`, itself native-image-friendly with no extra reflection
+config needed for simple no-arg-constructor implementations). The DTO mapper registry follows the
+same per-module aggregation + `META-INF/services` registration shape, giving `mapTo(Class)` a
+concrete generated implementation to dispatch through at runtime without reflection anywhere in
+the chain.
+
+### mapTo(Dto.class) runtime wiring (implemented)
+
+`query.mapTo(dtoType)` returns a `MappedQuery<D>` (`findList()`/`findOne()`/`findOneOrEmpty()`/
+`findStream()`/`findPagedList()`/`usingMaster(boolean)`/`usingTransaction(Transaction)`/`usingConnection(Connection)`).
+On first use it resolves the generated `DtoMapper<S, D>` for the query's `(getBeanType(), dtoType)`
+pair via a `DtoMapperManager` (a `ServiceLoader`-backed aggregator over all generated
+`DtoMapperRegister`s, analogous to `DtoBeanManager`), then:
+
+- applies `mapper.fetchGroup()` to the query via `query.select(fetchGroup)` - the fetch/select spec
+  is entirely derived from the DTO's declared shape, no manual `.select()`/`.fetch()` needed;
+- forces `query.setUnmodifiable(true)` - the resulting entity graph is read-only input to the
+  mapper, and any DTO property whose source wasn't actually fetched fails fast with
+  `LazyInitialisationException` rather than silently lazy loading or returning `null`;
+- executes the query and maps the result(s) via `mapper.map(...)`/`mapper.mapList(...)`.
+
+An unregistered `(source, dtoType)` pair throws a `PersistenceException` with a suggested
+`@DtoMapping` fix, at first use (i.e. `findList()`/`findOne()`), not at `mapTo(dtoType)` call time.
+
+`MappedQuery<D>.usingMaster(boolean)`, `.usingTransaction(Transaction)`, and `.usingConnection(Connection)`
+all delegate directly to the underlying entity query, mirroring `Query`/`QueryBuilder`. This lets a
+caller retry against the master data source after a read-replica failure by calling
+`usingMaster(true)` on the *same* `MappedQuery` instance and re-invoking a find method - there's no
+need to rebuild the query and call `.mapTo(...)` again.
+
+`MappedQuery<D>.findStream()` mirrors `QueryBuilder#findStream()` - the underlying entity query is
+streamed (supporting very large result sets, potentially using multiple persistence contexts
+internally) and each entity is mapped to its target DTO lazily as the stream is consumed. One
+`DtoMapContext` is shared across the whole stream (not per-element), so identity de-duplication of
+nested DTOs (e.g. several `Contact`s sharing the same `Customer`) still holds even when the source
+entities are never materialized into one `List` at all. As with the entity-level `findStream()`,
+callers must consume it via try-with-resources to ensure the underlying resources are closed.
+
+
+## Still open / to revisit during implementation
+
+- Whether `.fetch(...)` calls can still be layered on top of a `mapTo(Dto.class)` query for explicit
+  overrides. Currently the mapper's `fetchGroup()` is the *only* source of the fetch spec - any
+  `.select()`/`.fetch()` calls made before `.mapTo(...)` are overwritten by it.
+- Whether `@DtoPath`/`@DtoRef` need additional attributes beyond a bare path/marker (e.g. an explicit
+  target type on `@DtoRef` for disambiguation) once real DTOs with more complex shapes are codegen'd.
+- Behavior when a DTO property has no matching entity property and no `@DtoPath`/`@Formula2` override
+  (fail at codegen time, most likely, consistent with the "fail fast" philosophy).
+- `@Formula2`-on-DTO mapping to Blaze-Persistence/QueryDSL-style computed properties - not yet
+  implemented (see requirements doc); a narrower validation-only variant was attempted and rejected
+  as not distinct enough from `@DtoPath` (see "Formula2-on-DTO scope" above). The broader ad-hoc-SQL
+  case likely doesn't need a dedicated DTO feature at all - see "Ad-hoc computed/formula properties"
+  above for the `@Entity @View`/`@Sql` alternative.
+- **Fetch-path collision between a `NESTED_ONE`/`NESTED_MANY` property and a `@DtoPath` property -
+  found and fixed**: `DtoMapperWriter.fetchGroupChainCalls()` builds one `.fetch(path, ...)`
+  chain-call per distinct fetch path, but the underlying `OrmQueryDetail.fetch(...)` unconditionally
+  **overwrites** (rather than merges) any existing entry for the same path key. If a DTO declared a
+  `NESTED_ONE`/`NESTED_MANY` property AND a `@DtoPath` property whose fetch-path prefix is the *exact
+  same* path (e.g. a nested `AddressDto billingAddress` alongside `@DtoPath("billingAddress.line1")`
+  on the same DTO - both resolve to fetch path `"billingAddress"`), the generator would emit two
+  `.fetch("billingAddress", ...)` calls and the second would silently discard the first's selected
+  properties. Merging wasn't practical - the nested property's `.fetch(path, mapper.fetchGroup())`
+  call passes another mapper's own pre-built, immutable, shared `FetchGroup`, so there's no clean way
+  to splice an extra scalar property into it at the call site. Fixed instead with a **fail-fast
+  compile-time error**: `DtoMapperWriter` now detects the collision and raises a clear
+  `ctx.logError(...)` (annotation-processor `ERROR` diagnostic, fails the compile) naming the
+  colliding property and fetch path, and suggesting the two ways out - move the property onto the
+  nested DTO type instead, or pick a `@DtoPath` that reaches a different, non-colliding path (as
+  `ContactDto.customerCity` already does deliberately, per its own comment, using a 3-segment path).
+  Verified empirically by compiling a small reproduction with a colliding `@DtoPath` and confirming
+  the expected error fires; a permanent regression test
+  (`DtoMapperFetchPathCollisionTest` in `querybean-generator`) now runs this same repro directly
+  through `javax.tools.JavaCompiler` with the `Processor` registered, asserting the compile fails with
+  the expected diagnostic message.
+- **Compile-time verification of `select(...).asDto(...)` (r6, aspirational) - explored and closed as
+  rejected**: raw SQL is an opaque `String` at compile time, and even the typed query-bean
+  `.select(...)` form only type-checks against the *entity* - the match to the target DTO's constructor
+  still happens at runtime via reflection (`DtoQueryPlanConstructor`), and the `.asDto(...)` call site
+  can be arbitrarily distant from the `.select(...)` call, so there's no fixed AST shape an annotation
+  processor could reliably verify (unlike QueryDSL, whose compile-time safety actually comes from typed
+  `Projections.constructor(...)`/generated Q-type constructor calls, not from checking a select-list
+  against a DTO). `mapTo(Dto.class)` already closes the underlying gap in the tractable direction - it
+  derives the select/fetch spec *from* the DTO's declared shape at APT time, so it is compile-time safe
+  by construction. Recommend `mapTo()` whenever compile-time-checked DTO projection matters, and treat
+  `asDto()`/`findDto()` as the flexible, runtime-checked escape hatch for raw/dynamic SQL. See
+  `dto-mapping-requirements.md` requirement r6.
+- **Custom property conversion (`@DtoConvert`/`@DtoMixin`, r13/r14) - implemented**: motivated by a
+  real hand-written mapper (`DriverMapper`, central-access) needing both a dependency-free scalar
+  coercion (`short` -> `boolean`) and a dependency-backed conversion (AES decryption via an injected
+  cipher). Final design (see `dto-mapping-requirements.md` section E), as built:
+  - `@DtoConvert(value = ConverterType.class, method = "name")` on a DTO property (combinable with
+    `@DtoPath`); the generator dispatches on whether the referenced method is `static` - static means a
+    direct inlined static call (no registration, covers common reusable coercions), instance means
+    dispatch via a new `DtoConverterManager.get(ConverterType.class).method(...)` call, with the
+    resolved instance wired as a real constructor parameter/field on the generated mapper (same shape
+    as existing nested-mapper constructor injection). Multiple properties on the same mapper sharing
+    the same converter type are deduplicated to a single constructor parameter/field
+    (`DtoBeanMeta.converterDeps()`).
+  - `DtoConverterManager` (`ebean-api`, `io.ebean` package) is a small, narrowly-scoped static put/get
+    bridge - the app registers an already-DI-constructed converter singleton (e.g. built by
+    avaje-inject) *before* building the `Database`. This is a deliberate, narrow exception to the
+    general no-static-mutable-state convention: `ServiceLoader`-discovered, no-arg-constructed
+    generated code (`EbeanDtoMapperRegister`) has no other way to reach an already-DI-constructed
+    singleton. `DtoConverterManager.get(type)` throws immediately if nothing was registered for that
+    type, so a missing converter fails fast at Database-startup time (an eager field initializer on
+    `EbeanDtoMapperRegister`, and equally on each mapper's own no-arg constructor, which resolves the
+    same way via `DtoConverterManager.get(...)` for standalone/test construction), not lazily on first
+    use - `DtoMapperRegister`'s `mapperFor(...)` signature and `DtoMapperManager` are otherwise
+    completely unchanged, as originally planned.
+  - Two alternatives were explored and rejected first: (a) a `DtoMapContext.service(Class)` lookup -
+    wrong lifetime, `DtoMapContext` is a short-lived per-call identity-cache only; (b) a
+    `ServiceLoader`-discovered `DtoConverterSource` SPI mirroring `DtoMapperRegister` itself - can't
+    bridge to an *already* DI-constructed dependency without reconstructing/duplicating it.
+  - `@DtoMixin(Target.class)` - a companion type overlaying `@DtoPath`/`@DtoConvert`/`@DtoRef`
+    annotations onto a DTO that can't be annotated directly (e.g. OpenAPI-generated). Discovered via
+    `roundEnv.getElementsAnnotatedWith(...)` (added to `Processor.getSupportedAnnotationTypes()`,
+    since - unlike `@DtoPath`/`@DtoRef`/`@DtoConvert` - a mixin doesn't annotate an already-iterated
+    field of a known `@DtoMapping` target, so it can't be found lazily). `DtoMappingReader` resolves
+    each target property's annotations from the field itself first, falling back to a same-named
+    method on the registered mixin (`DtoMappingReader.prismOn(...)`) - directly mirrors avaje-jsonb's
+    proven `@Json.MixIn` mechanism.
+  - Implemented in `ebean-annotation` (`DtoConvert`, `DtoMixin`), `ebean-api` (`DtoConverterManager`),
+    and `querybean-generator` (`DtoConverterMeta`, `DtoBeanMeta.converterDeps()`,
+    `DtoMappingReader`/`DtoMapperWriter`/`DtoMapperRegisterWriter` changes). Test coverage:
+    `tests/test-dto-mapping` `TestDtoConvert` (static + instance dispatch, fail-fast unregistered-type
+    check) and `TestDtoMixin` (mixin overlay, including instance-dispatch conversion resolved purely
+    from mixin-declared annotations). The instance-dispatch converter is registered via a
+    `DatabaseConfigProvider` (ServiceLoader hook run before the `Database` is built) rather than a test
+    `@BeforeAll`, since `EbeanDtoMapperRegister`'s mapper fields (including any needing
+    `DtoConverterManager`) are all constructed eagerly during `Database` startup, which can be
+    triggered by whichever test class in the module happens to run first.
+
+- **Fixed (validation phase, found via `central-access`): `@DtoPath` through a computed/derived
+  getter now fails at compile time, with an explicit `requires()` escape hatch.** `@DtoPath`
+  assumes every dotted segment names a real, fetchable Ebean bean property - so a path like
+  `@DtoPath("currentMachine.organisationMachine.registrationPlate")`, where `getOrganisationMachine()`
+  is a hand-written derived getter (not a real relation/column), used to **compile cleanly** (the
+  codegen had no way to tell it apart from a real property from source alone) but **fail at
+  runtime** with a `PersistenceException: No property found for [organisationMachine] in
+  expression ...`, because the generated `FetchGroup` builder tried to `fetch`/`select` it as if it
+  were a real Ebean property.
+  - Two genuinely separate sub-problems: (1) *detecting* that a path segment isn't a real,
+    fetchable property - solvable at compile time, since a real persistent property always has a
+    backing field (Ebean requires one to enhance), checked via `javax.lang.model`
+    (`ElementFilter.fieldsIn(...)` over the type + superclass chain, see `DtoMappingReader.hasField(...)`);
+    versus (2) *knowing what the computed getter needs fetched* to execute safely - not solvable at
+    compile time without full static/bytecode analysis of the getter's method body, out of scope.
+  - Resolution: don't attempt to infer (2) automatically. When `DtoMappingReader` detects a `@DtoPath`
+    segment with no backing field, it now fails fast at compile time (`ctx.logError(...)`) unless the
+    developer explicitly declares the real entity paths that must be fetched via
+    `@DtoPath(requires = {...})` (dot-notation, same convention as `@DtoPath`'s own `value()`) - e.g.
+    `@DtoPath(value = "primaryContact.lastName", requires = "contacts")` where `getPrimaryContact()`
+    picks the first entry out of the `contacts` collection. The real prefix before the computed
+    segment (if any) is automatically combined with the declared `requires()` paths, so the developer
+    doesn't need to redundantly repeat it. Declared paths are emitted as bare `.fetch(path)` calls in
+    the generated `FetchGroup` (distinct from the `.fetch(path, "props")` shape used for ordinary
+    scalar `@DtoPath` properties, since there's no specific target property list to narrow to here).
+  - **The zero-extra-fetch case is also supported, via an explicit `requires = {}`** - e.g.
+    `@DtoPath(value = "idBadge", requires = {})` where `getIdBadge()` derives purely from `id`
+    (always fetched regardless). An explicit empty array confirms "nothing extra needed", distinct
+    from omitting `requires()` entirely ("not yet considered", still a compile error) - `requires()`
+    itself can't tell the two cases apart (both read back as an empty `List`), so `DtoMappingReader`
+    checks the avaje-prism-generated `DtoPathPrism.values.requires()` instead, which returns `null`
+    only when the member was left at its default (i.e. omitted from source). `DtoPropertyMeta`
+    correspondingly carries `hasComputedSegment()` as its own boolean flag (set whenever a computed
+    segment was detected at all), independent of whether `requiredFetchPaths()` happens to be empty -
+    an earlier version conflated the two (inferring "has a computed segment" from "has a non-empty
+    requiredFetchPaths list"), which broke exactly this explicit-empty case by falling through to the
+    ordinary scalar `.select(...)` path and failing at runtime with `PersistenceException: Property
+    not found - idBadge` (`idBadge` isn't a real Ebean property, so it can't be selected).
+  - Implemented in `ebean-annotation` (`DtoPath.requires()`), and `querybean-generator`
+    (`DtoMappingReader` computed-segment detection/validation, `DtoPropertyMeta.requiredFetchPaths()`/
+    `hasComputedSegment()`, `DtoMapperWriter.fetchGroupChainCalls()` bare-fetch emission). Test
+    coverage: `tests/test-dto-mapping` `ComputedPathDto`/`TestComputedPath` (happy path, `requires`
+    correctly fetches the dependency and the mapped value is correct), `ComputedPathNoFetchDto`/
+    `TestComputedPathNoFetch` (explicit `requires = {}`, genuinely nothing extra needed), and
+    `querybean-generator`'s `DtoMapperComputedPathTest` (negative case - omitting `requires` on a
+    computed segment is a compile-time `ERROR` diagnostic, verified via direct `javax.tools.JavaCompiler`
+    compilation, mirroring `DtoMapperFetchPathCollisionTest`).
+  - Known gap: the dedup between the computed segment's required fetch paths and existing
+    `pathSelect`/`nestedAssocPaths` keys in `DtoMapperWriter` is a simplified exact-path-string check
+    (skip emitting a duplicate `.fetch(path)`), not full collision detection like the existing
+    NESTED_ONE/MANY vs `@DtoPath` check - a bare `fetch(path)` and an existing `fetch(path,
+    "specific,props")` for the same path string are not merged/reconciled, just left as two separate
+    calls if that edge case arises.
+
+- **Fixed: a single-hop `@DtoPath` rename through a computed/derived getter whose return type is
+  itself a registered nested DTO (`NESTED_ONE`/`NESTED_MANY`, not `SCALAR`) bypassed the
+  computed-segment validation above entirely.** E.g. `@DtoPath("primaryContact")` where the DTO
+  field's declared type is `ContactDto` (a type with its own `@DtoMapping(source = Contact.class,
+  target = ContactDto.class)`) and `getPrimaryContact()` is a computed getter with no backing
+  field on `Customer`. This resolves to a single-segment path, so `DtoMappingReader.resolveProperty()`
+  took its `properties.size() == 1` nested-lookup shortcut and returned early - before the
+  `computedFrom`/`requires()` validation block (added for the `SCALAR` case above) ever ran. The
+  generated `FetchGroup` then emitted a broken `fetch("primaryContact",
+  contactMapper.fetchGroup())` call (`"primaryContact"` isn't a real Ebean fetch path), failing at
+  runtime rather than compile time - the exact class of bug the `SCALAR` fix was meant to close off
+  entirely.
+  - Resolution: restructured `resolveProperty()` so the computed-segment detection/validation block
+    runs *before* the `properties.size() == 1` nested-lookup branch, so both `SCALAR` and
+    `NESTED_ONE`/`NESTED_MANY` paths share the same detection/validation. `DtoPropertyMeta` gained a
+    matching constructor overload for `NESTED_ONE`/`NESTED_MANY` carrying `computedSegment`/
+    `requiredFetchPaths`. In `DtoMapperWriter.fetchGroupChainCalls()`, a `NESTED_ONE`/`NESTED_MANY`
+    property with `hasComputedSegment()` true is routed into `extraFetchPaths` (the same bare
+    `.fetch(path)` mechanism as the `SCALAR` case) instead of emitting `fetch(path,
+    mapper.fetchGroup())` - since the nested mapper's own `FetchGroup` requirements can't be
+    meaningfully attached under a path name that doesn't exist on the source entity.
+  - Note the nested mapper's *own* fetch requirements (e.g. if `ContactDto` itself needed
+    `customer.billingAddress`) are **not** automatically propagated up through a computed segment -
+    only whatever the computed getter itself needs (via `requires()`) is fetched. The nested
+    mapper's `map(...)` call still works via plain Java method invocation regardless (Ebean
+    transparent lazy loading covers any gap), but relying on that silently reintroduces N+1 queries,
+    so the nested DTO used through a computed segment should ideally be a "leaf" shape needing
+    nothing beyond what `requires()` already declares.
+  - Implemented in `querybean-generator` (`DtoMappingReader.resolveProperty()` restructuring,
+    `DtoPropertyMeta`'s new constructor overload, `DtoMapperWriter.fetchGroupChainCalls()`). Test
+    coverage: `tests/test-dto-mapping` `ContactLeafDto`/`ComputedNestedDto`/`TestComputedNestedPath`
+    (happy path - generated `FetchGroup` is `.select("id").fetch("contacts")`, no broken
+    `fetch("primaryContact", ...)` call, and the mapped value is correct end-to-end), and
+    `querybean-generator`'s `DtoMapperComputedPathTest#dtoPathThroughComputedGetter_targetingNestedDto_withoutRequires_expectCompileError`
+    (negative case, mirroring the `SCALAR` one). The `NESTED_MANY` variant (a computed getter
+    returning a `List` of a type with its own registered nested DTO mapping) shares the identical
+    code path but had no dedicated regression test until later confirmed via `Customer
+    .getRecentContacts()` / `ComputedNestedListDto` / `TestComputedNestedListPath` (coverage only,
+    not a bug fix - passed cleanly first try, confirming the shared code path does work end-to-end
+    for both `NESTED_ONE` and `NESTED_MANY`).
+
+- **Fixed: `@DtoRef` never checked for a computed/derived association getter at all.** Unlike
+  `@DtoPath`, `@DtoRef`'s association name (derived by stripping the `Id` suffix off the field
+  name, e.g. `primaryContactId` -> `primaryContact`) was never checked against `hasField(...)` -
+  so `@DtoRef` on a computed getter (e.g. `getPrimaryContact()` picking the first entry out of a
+  `contacts` collection) compiled cleanly and generated a broken `FetchGroup.select("primaryContact")`
+  call (`"primaryContact"` isn't a real Ebean property), failing at runtime rather than compile
+  time - the same class of bug as the original `@DtoPath` fix, just entirely unaddressed for
+  `@DtoRef`'s separate code path.
+  - Resolution: `@DtoRef` gained its own `requires()` attribute (dot-notation, same convention and
+    explicit-empty semantics as `@DtoPath#requires()`, using the same `DtoRefPrism.values.requires()
+    == null` omitted-vs-explicit-empty technique). `DtoMappingReader`'s `@DtoRef` branch now checks
+    `hasField(meta.source(), assocName)` and fails fast at compile time (`ctx.logError(...)`) when
+    the association has no backing field and `requires()` wasn't specified. `DtoPropertyMeta`'s
+    `REF` properties now carry `computedSegment`/`requiredFetchPaths` through the existing fields
+    (no new constructor needed - the full constructor already had the right shape).
+    `DtoMapperWriter.fetchGroupChainCalls()`'s `REF` case now checks `hasComputedSegment()` and
+    routes into `extraFetchPaths` (bare `.fetch(path)`) instead of `rootSelect.add(assoc)` when
+    true - the value expression itself (`source.getPrimaryContact().getId()`, null-guarded) is
+    unaffected, since it's plain Java method invocation regardless of whether the association name
+    is a real Ebean property.
+  - Implemented in `ebean-annotation` (`DtoRef.requires()`), and `querybean-generator`
+    (`DtoMappingReader`'s `@DtoRef` branch, `DtoMapperWriter.fetchGroupChainCalls()`'s `REF` case).
+    Test coverage: `tests/test-dto-mapping` `ComputedRefDto`/`TestComputedRefPath` (happy path -
+    generated `FetchGroup` is `.select("id").fetch("contacts")`, no broken `select("primaryContact")`
+    call, and the mapped id is correct end-to-end), and `querybean-generator`'s
+    `DtoMapperComputedPathTest#dtoRefThroughComputedGetter_withoutRequires_expectCompileError`
+    (negative case, mirroring the `@DtoPath` ones).
+
+- **Fixed: `requires()` path values themselves were never validated against the source type's
+  real property graph.** `@DtoPath(requires = {...})`/`@DtoRef(requires = {...})` values are
+  handed straight through to `FetchGroup.fetch(...)` unmodified - a typo (e.g. `requires =
+  "contactz"` for the real `contacts` property) compiled cleanly, since only the *computed
+  segment itself* was checked against `hasField(...)`, not the developer-declared dependency
+  paths meant to fix it. That silently reintroduced the exact runtime `PersistenceException` the
+  whole `requires()` escape hatch exists to prevent, just one step removed and harder to spot.
+  - Resolution: added `DtoMappingReader.validateRequiresPath(...)`, which walks each dot-notation
+    segment of a declared `requires()` value from the source root (`meta.source()`), checking
+    `hasField(...)` at every hop exactly like `@DtoPath#value()`'s own segments are checked, and
+    unwrapping a `java.util.List`-typed intermediate hop to its element type (via
+    `listElementType(TypeMirror)`) so a collection segment followed by a further hop resolves
+    correctly - needed a new `getterReturnTypeMirror(...)` helper (returning the raw `TypeMirror`
+    rather than converting straight to `TypeElement`, which can't distinguish a `List` from any
+    other declared type) alongside the existing `getterReturnType(...)`. Called for every entry in
+    `pathPrism.requires()`/`refPrism.requires()` right after they're read, for both the `@DtoPath`
+    and `@DtoRef` branches. The already-validated real prefix (segments before the computed one in
+    a `@DtoPath#value()`) is intentionally *not* re-validated, since it was already checked while
+    walking `value()` itself.
+  - Implemented in `querybean-generator` (`DtoMappingReader.validateRequiresPath(...)`,
+    `getterReturnTypeMirror(...)`, called from both the `@DtoPath` and `@DtoRef` branches). Test
+    coverage: `querybean-generator`'s
+    `DtoMapperComputedPathTest#dtoPathRequires_withTypoInPathValue_expectCompileError` (negative
+    case - a typo'd `requires()` segment is a compile-time `ERROR` diagnostic); existing
+    `tests/test-dto-mapping`/`central-access` suites (real multi-segment `requires()` values like
+    `"currentMachine.organisationMachines"`) continue to pass unchanged, confirming the validation
+    doesn't false-positive on legitimate paths.
+
+- **Fixed: a bare, full `requires()` fetch and a sibling property's narrowed `@DtoPath` fetch of
+  the exact same path silently conflicted, with the narrow one always (incorrectly) winning.**
+  `DtoMapperWriter.fetchGroupChainCalls()`'s dedup logic used to skip emitting a computed
+  segment's bare `fetch(path)` call whenever another property's `@DtoPath` already had a narrowed
+  `fetch(path, "specific,props")` entry for that exact path string - on the assumption the two
+  were interchangeable/redundant. They aren't: `FetchGroup`'s builder (`OrmQueryDetail.fetch(...)`)
+  keys fetch calls by path in a plain `Map` and **replaces** rather than merges same-path entries,
+  so whichever call format was emitted meant the *other* was silently discarded. Since the narrow
+  entry was always emitted first and the bare one skipped whenever it existed, the narrow selection
+  always won - meaning a computed getter's `requires()` declaration could be completely ignored
+  whenever an unrelated sibling `@DtoPath` happened to narrow-select the exact same path, leaving
+  whatever extra properties the computed getter actually touches unfetched (a silent lazy load, or
+  a hard `LazyInitialisationException` outside a persistence context).
+  - Resolution: reversed the priority - `fetchGroupChainCalls()` now skips a narrowed `pathSelect`
+    entry when `extraFetchPaths` (the computed segment's `requires()`) declares the exact same
+    path, letting the bare, full `fetch(path)` call win instead. This is always safe since a full
+    fetch is a superset of any narrower property selection - the narrow entry's own properties are
+    included within it regardless. The existing `nestedAssocPaths` priority (a `NESTED_ONE`/
+    `NESTED_MANY` property's full `fetch(path, mapper.fetchGroup())` always wins over a bare
+    `fetch(path)`) was correct already and left unchanged - a nested mapper's own `FetchGroup` is
+    strictly richer than either form and must not be replaced by either.
+  - Implemented in `querybean-generator` (`DtoMapperWriter.fetchGroupChainCalls()`). Test coverage:
+    `tests/test-dto-mapping` `FetchCollisionDto`/`TestFetchCollisionPath`, plus a new computed
+    getter `Customer.getBillingSummary()` (reads `billingAddress.getLine1()`, deliberately a
+    different `Address` property to the `city` narrowly selected by a sibling `@DtoPath` on the
+    same DTO) - confirmed to reproduce `LazyInitialisationException: Property not loaded: line1`
+    when the fix is reverted, and pass cleanly (correct `line1`-derived value, generated
+    `FetchGroup` is `.select("id").fetch("billingAddress")` with no narrowed variant at all) with
+    it in place.
+
+- **Fixed: two `@DtoMixin` companion types targeting the same DTO class silently conflicted, with
+  the second-processed one winning.** `DtoMappingReader.collectMixins()` keyed a single
+  `mixinsByTarget` map by the target DTO's FQN, and `Map.put(...)` unconditionally overwrote any
+  existing entry - so if two mixin interfaces (e.g. a legitimate one plus an accidental duplicate,
+  or two independently-added mixins that both happened to target the same generated/unowned DTO)
+  both declared `@DtoMixin(SameDto.class)`, whichever was visited last by
+  `roundEnv.getElementsAnnotatedWith(...)` silently won, and *all* of the other mixin's
+  `@DtoPath`/`@DtoRef`/`@DtoConvert` overlays were discarded with no diagnostic at all.
+  - Resolution: `collectMixins()` now checks for an existing registration before storing a new one
+    and raises a compile `ERROR` naming both the target and the already-registered mixin's
+    qualified name, rather than silently overwriting it.
+  - Implemented in `querybean-generator` (`DtoMappingReader.collectMixins()`). Test coverage: new
+    negative compile-error test `DtoMapperComputedPathTest#duplicateDtoMixin_forSameTarget_expectCompileError`
+    (two minimal `@DtoMixin(FooDto.class)` interfaces both declaring a `bar()` method, compiled
+    together, asserting the `Duplicate @DtoMixin` diagnostic is raised); existing
+    `tests/test-dto-mapping` `TestDtoMixin` (single, legitimate mixin usage) continues to pass
+    unchanged.
+
+- **Fixed: `@DtoRef` and `@DtoPath` both present on the same field silently conflicted, with
+  `@DtoRef` always (invisibly) winning.** `resolveProperty()` checked `refPrism != null` first and
+  returned immediately whenever present, so a field carrying both annotations at once - whether by
+  copy/paste mistake, a half-finished rename from one style to the other, or simple confusion
+  between the two escape hatches - had its `@DtoPath` completely ignored with no diagnostic at all.
+  - Resolution: `resolveProperty()` now resolves both prisms upfront and raises a compile `ERROR`
+    naming the field when both are present, rather than silently picking `@DtoRef` and discarding
+    `@DtoPath`.
+  - Implemented in `querybean-generator` (`DtoMappingReader.resolveProperty()`). Test coverage: new
+    negative compile-error test `DtoMapperComputedPathTest#dtoRefAndDtoPath_onSameField_expectCompileError`
+    (a field carrying both `@DtoRef` and `@DtoPath("bar.id")` over a real, non-computed association,
+    isolating the conflict diagnostic from the separate computed-getter `requires()` diagnostics).
+
+- **Fixed: `@DtoConvert` on a `NESTED_ONE`/`NESTED_MANY` property was silently ignored.**
+  `resolveProperty()` resolves the property's `DtoConverterMeta` unconditionally up front (before
+  it's known whether the property will resolve to `SCALAR`/`REF`/`NESTED_ONE`/`NESTED_MANY`), but
+  only the `SCALAR`/`REF` `DtoPropertyMeta` constructors actually accept/store a converter - the
+  `NESTED_ONE`/`NESTED_MANY` constructor calls never took one, so a resolved converter was simply
+  dropped on the floor with no diagnostic. A developer adding `@DtoConvert` to a nested-DTO field
+  (e.g. hoping to post-process the nested mapper's result) would see it silently do nothing -
+  `DtoMapperWriter.propertyValueExpression()`'s `NESTED_ONE`/`NESTED_MANY` cases call straight into
+  `mapperFieldName(property) + ".map(...)"`/`".mapList(...)"` with no converter wrapping at all.
+  - Resolution: added `rejectConverterOnNested(...)`, called at each of the four call sites that
+    construct a `NESTED_ONE`/`NESTED_MANY` `DtoPropertyMeta` (the single-hop `@DtoPath`-rename
+    branch's two cases, and the plain non-`@DtoPath` branch's two cases) - raises a compile `ERROR`
+    naming the field whenever a converter was resolved for it, rather than silently discarding it.
+  - Implemented in `querybean-generator` (`DtoMappingReader.resolveProperty()`,
+    `rejectConverterOnNested()`). Test coverage: new negative compile-error test
+    `DtoMapperComputedPathTest#dtoConvertOnNestedOne_expectCompileError` (a `NESTED_ONE` field
+    carrying `@DtoConvert` over a legitimately nested, separately-`@DtoMapping`-registered type);
+    existing `tests/test-dto-mapping` suite (no nested property currently combines `@DtoConvert`
+    with `NESTED_ONE`/`NESTED_MANY`) continues to pass unchanged, confirming no false positives on
+    plain nested properties.
+
+- **Fixed: `@DtoConvert(method = ...)` resolution ignored parameter arity/overloads.** The shared
+  `findMethod(type, name)` helper (also used for the builder's `build()` lookup and `@DtoMixin`
+  companion-method lookup) matches purely by simple name - the first `ExecutableElement` found -
+  with no arity or parameter-type check at all. For `@DtoConvert` specifically this is a real risk:
+  its documented contract is a method "taking the source property value and returning the
+  converted DTO property value" (i.e. exactly one parameter), but a shared/reusable conversion
+  utility class is a very plausible place to have multiple same-named overloads (e.g. `format
+  (Instant)` and `format(LocalDate)`) - `findMethod` would silently bind to whichever one
+  `ElementFilter.methodsIn` happened to return first, independent of which one the developer
+  actually meant, generating either a confusing arity/type-mismatch compile error in the generated
+  mapper or, if both overloads happened to be call-compatible, silently invoking the wrong one.
+  - Resolution: added a dedicated `findConverterMethod(...)` (used only by `resolveConverter()`,
+    leaving the shared `findMethod()` untouched for the builder/mixin call sites which have their
+    own, different arity expectations) that filters same-named candidates down to those taking
+    exactly one parameter. Zero matches raises a clear "not found ... taking exactly one
+    parameter" error; more than one match (multiple 1-arg overloads sharing the name) raises an
+    "ambiguous - N overloads take exactly one parameter" error, since `@DtoConvert` has no
+    parameter-type-based way to disambiguate and the developer must rename one of the overloads.
+  - Implemented in `querybean-generator` (`DtoMappingReader.resolveConverter()`,
+    `findConverterMethod()`). Test coverage: new negative compile-error tests
+    `DtoMapperComputedPathTest#dtoConvertMethod_withAmbiguousOverloads_expectCompileError` (two
+    same-named 1-arg overloads) and `#dtoConvertMethod_withWrongArity_expectCompileError` (a
+    same-named 0-arg method, no 1-arg candidate at all); existing `tests/test-dto-mapping`
+    converter usage (a single, unambiguous 1-arg method per converter type) continues to resolve
+    and pass unchanged.
+
+## References
+
+- Requirements: [dto-mapping-requirements.md](./dto-mapping-requirements.md)
+- Issue: https://github.com/ebean-orm/ebean/issues/2540
+- MapStruct cycle mapping: https://mapstruct.org/documentation/stable/reference/html/#mapping-object-cycles

docs/dto-mapping-requirements.md

@@ -0,0 +1,337 @@
+# Nested DTO Mapping — Requirements
+
+Design requirements distilled from [issue #2540 "Support nested DTO mapping"](https://github.com/ebean-orm/ebean/issues/2540),
+reviewed against comparable features in QueryDSL (`@QueryProjection`) and Blaze-Persistence (`@EntityView`).
+
+## Context
+
+Ebean already supports:
+
+- Partial/flat DTO queries via `DB.findDto(...)` and `query.select(...).asDto(Dto.class)`.
+- `@Formula` / `@Formula2` — path-based, auto-joined computed SQL expressions, but only on managed entities.
+- `query.setUnmodifiable(true)` — builds a read-only, non-lazy-loading entity graph (`InterceptReadOnly`,
+  see PR #2626). Accessing an unloaded property throws `LazyInitializationException`; mutating throws
+  `UnmodifiableEntityException`.
+
+Unlike Hibernate, Ebean does dirty-detection on the bean itself (no dynamic proxies), so there is very little
+extra cost to an entity-graph query versus a DTO query. This makes an **unmodifiable entity graph** a cheap,
+natural intermediate representation to map *from* when producing a DTO graph — we don't need Blaze/Hibernate's
+proxy-based `EntityView` mechanism to get the performance benefit they are chasing.
+
+The goal is nested DTO graph support (DTOs containing ToOne/ToMany child DTOs), not just today's flat DTOs,
+while keeping DTOs as plain, framework-unattached classes.
+
+## Accepted Requirements
+
+### A. Nested DTO graphs
+
+- **Support nested DTO graphs (ToOne/ToMany)**
+  Allow mapping a query result into a DTO graph where DTO fields are themselves DTOs (ToOne) or
+  `List`/`Set<Dto>` (ToMany), not just flat DTOs. Use the existing `setUnmodifiable(true)` entity graph as
+  the intermediate, de-duplicated, identity-consistent source to map from.
+  *Inspiration: Blaze `@EntityView` subviews/subview collections; Jimmer fetcher DTOs.*
+
+- **Auto-generated entity → DTO graph mapper**
+  Given an unmodifiable entity graph plus a target nested DTO type, generate (via annotation processing,
+  reflection-free) a mapper that walks the graph and populates the DTO graph, matching properties by
+  name/type with override annotations for renames, computed values, and collection element types.
+  *Inspiration: Blaze `@EntityView` + subview mapping; conceptually similar to MapStruct but Ebean-generated
+  and graph/identity aware.*
+
+- **Identity-aware de-duplication in nested collections**
+  When mapping nested collections referencing the same underlying entity instance multiple times, reuse the
+  same DTO instance (mirrors Blaze/Jimmer identity semantics) rather than producing independent copies.
+  *Inspiration: Blaze/Jimmer identity handling.*
+
+### B. Formula-style DTO annotations
+
+- **`@Formula2`-like annotations on DTO fields**
+  Bring the existing `@Formula` / `@Formula2` concept (auto-joined, path-based computed SQL expressions) to
+  DTO classes so a DTO field can request a computed/aggregated value with the join auto-derived, instead of
+  only being available on managed entities.
+  *Inspiration: User suggestion; Ebean `@Formula2`; Blaze `@Mapping` computed expressions.*
+  *Status: a narrower version (pulling in an existing entity-level `@Formula2` by path) was implemented and
+  then rejected - for the common same-name case it generated code identical to a plain unannotated field, so
+  the annotation added no real value beyond a codegen-time validation. See `docs/dto-mapping-design.md`
+  ("Formula2-on-DTO scope" and "Ad-hoc computed/formula properties" sections). The broader goal - arbitrary
+  ad-hoc computed SQL on a DTO field - is better served by modelling the computed value as its own
+  `@Entity @View`/`@Sql` read entity and mapping *that* into a plain DTO, reusing the existing (already
+  accepted) nested-DTO mapping machinery rather than a new DTO-level annotation.
+
+- **Path-based property mapping annotation on DTO**
+  Allow a DTO field or constructor param to be annotated with a source path expression (e.g. `parent.name`)
+  so Ebean can auto-derive the select clause plus joins for nested/renamed properties, reducing manual
+  constructor wiring for non-trivial mappings.
+  *Inspiration: Blaze `@Mapping`; QueryDSL constructor expressions.*
+
+### C. Compile-time safety
+
+- **Compile-time verification of `select(...).asDto(...)` mapping** *(explored, rejected as impractical -
+  `mapTo()` accepted as the alternative)*
+  Today `select(props).asDto(Dto.class)` is only checked at runtime. Explored an annotation-processor
+  based mechanism to verify at compile time that selected properties match the DTO constructor or setters,
+  mirroring QueryDSL's `@QueryProjection` compile-time Q-type generation. Rejected as impractical: raw SQL
+  is an opaque `String` at compile time, and even the typed query-bean `.select(...)` form only
+  type-checks against the *entity* - the match to the target DTO still happens at runtime via reflection
+  (`DtoQueryPlanConstructor`), and the `.asDto(...)` call site can be arbitrarily distant from the
+  `.select(...)` call, so there's no fixed AST shape an annotation processor could reliably verify.
+  QueryDSL's actual compile-time safety comes from a different mechanism entirely - typed
+  `Projections.constructor(...)`/generated Q-type constructor calls, not from checking an
+  independently-built select-list against a DTO. `mapTo(Dto.class)` (see section A) already closes the
+  underlying gap in the opposite, tractable direction: it derives the select/fetch spec *from* the DTO's
+  declared shape at APT time, so it is compile-time safe by construction, with no separate select-list to
+  drift out of sync. Recommendation: document `mapTo()` as the compile-time-safe answer for DTO
+  projections, and treat `asDto()`/`findDto()` explicitly as the flexible, runtime-checked escape hatch
+  for raw/dynamic SQL.
+  *Inspiration: QueryDSL `@QueryProjection` compile-time Q-type generation.*
+
+- **Fail-fast on unmapped or lazy property access**
+  Ensure a clear, documented, minimal-ceremony way to fail fast if code touches a property not included in
+  the query projection, instead of silently lazy loading or returning null. `query.setUnmodifiable(true)`
+  already satisfies this (throws `LazyInitializationException`) — document/promote it as the answer, and
+  evaluate whether a lighter-weight flag decoupled from full unmodifiable/read-only semantics is needed.
+  *Inspiration: Original issue ask; already solved via `setUnmodifiable()` (PR #2626 `InterceptReadOnly`).*
+
+### D. Fetch strategy and performance
+
+- **Fetch strategy control for DTO graph relationships**
+  Existing entity query fetch hints (join vs. select/subselect secondary query, `+query`/`+lazy`) should
+  transparently carry over when the target of the query is a DTO graph rather than an entity graph.
+  `query.mapTo(Dto.class)` applies the DTO-derived `FetchGroup` only when the query has no
+  `select()`/`fetch()` already set - a manually tuned fetch spec always takes precedence and is never
+  overridden, allowing manual query optimisation when needed (at the cost of falling back to the
+  existing fail-fast-on-unmapped-property behaviour if the manual spec doesn't cover what the DTO needs).
+  *Inspiration: Blaze FETCH/SELECT/SUBSELECT fetch strategies.*
+
+- **Pagination support for DTO graph queries**
+  Confirm existing pagination works unchanged when projecting into nested DTO graphs.
+  *Inspiration: Blaze pagination and keyset pagination support.*
+
+### E. Custom property conversion
+
+- **Per-property custom scalar conversion (`@DtoConvert`)**
+  Motivated by real hand-written mapper code (`DriverMapper`, central-access) doing per-property scalar
+  coercion (`short` -> `boolean`) and dependency-backed conversion (AES decryption via an injected cipher).
+  Introduce a `@DtoConvert(value = ConverterType.class, method = "name")` annotation (combinable with
+  `@DtoPath` for source-getter override) on a DTO property. The generator dispatches based on whether the
+  referenced method is `static`:
+  - **Static method** -> a direct static call is inlined (`ConverterType.method(source.getX())`), zero
+    ceremony, no registration - covers common, reusable, dependency-free scalar coercions (e.g.
+    `short`/`boolean`, enum <-> `String`) that could apply across many unrelated entity/DTO pairs.
+  - **Instance method** -> dispatched via `DtoConverterManager.get(ConverterType.class).method(source.getX())`
+    and wired as a real constructor parameter/field on the generated mapper (same shape as existing
+    nested-mapper constructor injection) - covers conversions needing a real dependency (e.g. a cipher).
+  `DtoConverterManager` is a small, deliberately-scoped static put/get bridge: the app registers an
+  already-DI-constructed converter singleton (e.g. built by avaje-inject) *before* building the `Database`.
+  This is a narrow, accepted exception to the general no-static-mutable-state convention - it exists solely
+  to bridge an already-DI-constructed singleton into `ServiceLoader`-discovered, no-arg-constructed generated
+  code, which cannot otherwise reach a DI container. `DtoConverterManager.get(type)` throws immediately if
+  nothing was registered, so a missing converter fails fast at Database-startup time (an eager field
+  initializer on the generated `EbeanDtoMapperRegister`), not lazily on first use.
+  *Design exploration considered and rejected two alternatives first: (a) a `DtoMapContext.service(Class)`
+  lookup - rejected because `DtoMapContext` is a short-lived per-call identity-cache only, wrong lifetime for
+  a real singleton dependency; (b) a `ServiceLoader`-discovered `DtoConverterSource` SPI mirroring
+  `DtoMapperRegister` itself - rejected because a `ServiceLoader`-instantiated (no-arg) source cannot bridge
+  to an *already* DI-constructed dependency (e.g. a cipher needing config/secrets) without reconstructing it
+  itself, duplicating/bypassing the app's own DI-managed instance.*
+  *Inspiration: `DriverMapper` (central-access) hand-written pattern; MapStruct qualified converter methods.*
+  *Status: implemented - `@DtoConvert` (ebean-annotation), `io.ebean.DtoConverterManager` (ebean-api), and
+  querybean-generator codegen support (static/instance dispatch, constructor wiring deduplicated by converter
+  type). Test coverage: `tests/test-dto-mapping` `TestDtoConvert`.*
+
+- **Type-pair (package-level) custom scalar conversion**
+  Motivated by real hand-written mapper code (`EboxMapper`, central-access): the same conversion repeats
+  across many unrelated properties on one target - `DateUtils.toCalendar(...)` on ~9 fields,
+  `parseEnum(EnumType.class, value)` on ~3 - under today's `@DtoConvert` every one of those properties must
+  carry its own repeated annotation. MapStruct solves this by letting a conversion method be defined once
+  (in the mapper or a `uses = {...}` helper) and auto-applying it to *every* property whose source/target
+  types match that method's signature - no per-field wiring. Proposed: a package-level, repeatable
+  `@DtoConverters({ConverterType.class, ...})` (sibling to `@DtoMapping` in `package-info.java`) - the
+  generator indexes every public static/instance method on the referenced type(s) by `(paramType ->
+  returnType)`, then for any property whose source getter type doesn't already match the target field type
+  and which carries no explicit per-property `@DtoConvert`, looks up that type pair and wires it in
+  automatically (same static-vs-instance/`DtoConverterManager` dispatch rules as `@DtoConvert` today). An
+  explicit per-property `@DtoConvert` always overrides the type-level default. Deliberately no built-in
+  conversions shipped by Ebean itself (no implicit `Enum.valueOf`/`.name()`) - the app still owns
+  exception/null-handling semantics (e.g. `parseEnum`'s catch-and-null-on-bad-value), just declares it once
+  instead of per-field.
+  **Status: implemented.** `@DtoConverters(ConverterType.class, ...)` (a single non-repeatable annotation
+  taking a `Class<?>[]`, `@Target({PACKAGE, MODULE})`) is registered once per package/module alongside
+  `@DtoMapping`. The generator indexes every public, single-arg, non-void method on each referenced type by
+  exact `(paramType -> returnType)`; any SCALAR property (plain or `@DtoPath`-renamed) with no explicit
+  `@DtoConvert` and a source/target type mismatch is auto-wired to the matching method (a duplicate/ambiguous
+  type pair across the registered types is a compile-time processor error). List-element-wise conversion and
+  `@DtoRef` (FK-id) properties are out of scope. Test coverage:
+  `tests/test-dto-mapping/.../TestDtoConverters.java` (`UuidConverters`/`UuidShortCodeConverter`,
+  `ContactTypeConverterDto`) - covers same-name auto-dispatch, `@DtoPath`-renamed auto-dispatch, and explicit
+  `@DtoConvert` overriding the registered default.
+  *Inspiration: `EboxMapper` (central-access) hand-written pattern; MapStruct type-signature-matched
+  conversion methods.*
+
+- **`@DtoMixin` for DTOs that cannot be annotated directly**
+  Some DTOs are generated (e.g. from an OpenAPI spec) and not editable/annotatable, so `@DtoPath`/
+  `@DtoConvert`/`@DtoRef` cannot always be placed directly on the DTO. Introduce a `@DtoMixin(Target.class)`
+  companion interface/type, discovered by scanning the compilation round and overlaying its per-property
+  annotations onto the real target's properties by name-match - directly mirrors avaje-jsonb's
+  `@Json.MixIn` mechanism (`KingfisherMixin`/`CrewMateMixIn` pattern), a proven prior-art solution to the
+  exact same "can't annotate a generated/unowned type" problem.
+  *Inspiration: avaje-jsonb `@Json.MixIn`.*
+  *Status: implemented - `@DtoMixin` (ebean-annotation) and querybean-generator round-scanning/overlay
+  support (matches mixin methods to target properties by name, applying whichever of `@DtoPath`/`@DtoRef`/
+  `@DtoConvert` is present as if declared on the target field itself). Test coverage: `tests/test-dto-mapping`
+  `TestDtoMixin`.*
+
+### F. DI-friendly manual mapper usage
+
+- **Public `DtoMapperManager` with `get(Class<T> mapperType)` for DI**
+  Motivated by `DriverMapper`/`DriverService` (central-access): `DriverMapper` is a hand-written
+  `@Component` constructor-injected into `DriverService`. Moved `DtoMapperManager` from internal
+  (`io.ebeaninternal.server.dto`) to public `io.ebean` - unchanged `mapperFor(source, dto)`, plus a new
+  `get(Class<T> mapperType)` keyed by the generated mapper's own concrete class (e.g.
+  `manager.get(CustomerDtoMapper.class)`), for direct/concrete-typed DI injection. `DtoMapperRegister`
+  gained a default `mapperOfType(Class<T>)` method (non-breaking); the generator emits the real if-chain
+  body (mirrors `mapperFor`'s if-chain). `DtoMapperManager` has zero `Database` dependency (constructor
+  only does `ServiceLoader.load(DtoMapperRegister.class)`), so it can be constructed standalone,
+  independent of/before a `Database` - e.g. as an avaje-inject bean.
+  *Inspiration: `DriverMapper`/`DriverService` (central-access).*
+  *Status: implemented.*
+
+- **`DtoMapperManager` sharing via `DatabaseBuilder.putServiceObject`**
+  So `query.mapTo()` and application-injected mappers share the exact same `DtoMapperManager` instance
+  (and hence the same underlying generated mapper singletons) rather than each independently constructing
+  its own, `InternalConfiguration` checks `config.getServiceObject(DtoMapperManager.class)` first (mirrors
+  the existing `AutoMigrationRunner`/`GeoTypeProvider` `putServiceObject`/`getServiceObject` pattern),
+  falling back to constructing a default `new DtoMapperManager()` if none was supplied.
+  *Inspiration: user proposal following `DriverMapper`/`DriverService` review.*
+  *Status: implemented.*
+
+*Rejected: generator-emitted `builder(source)` method* - `DriverMapper` exposes `builder(cDriver)`
+returning a partially-populated `DriverBuilder` so callers can add extra caller-supplied fields (e.g.
+fleets) before `build()`. Rejected as a generator feature - `Driver`/`DriverSummary` already use
+avaje-recordbuilder's `@RecordBuilder`, which generates `Target.builder(existingInstance)`
+(seed-from-instance). The same effect is already achievable with zero ebean changes:
+`mapper.map(source)` then `Builder.builder(mapped).extraField(x).build()`. Documented as a recipe
+instead (see "Recipe: adding extra caller-supplied fields after mapping" in
+`docs/guides/mapping-entity-graphs-to-dtos.md`).
+
+### G. Large-target construction and shape variants
+
+- **Builder-based target construction for large DTOs**
+  Motivated by `UserService`/`User` (central-access): `User` is a 24-field OpenAPI-generated record with
+  a `@RecordBuilder`-generated `UserBuilder`, hand-mapped via a long fluent builder chain rather than a
+  positional constructor to stay readable/refactor-safe. The generator auto-detects a RecordBuilder-style
+  builder on the target (static `Target.builder()` + fluent per-property setters + `build()`) and uses
+  `Target.builder().prop(x)....build()` instead of `new Target(a, b, c, ...)` whenever (a) a builder is
+  detected and (b) the target has more than a threshold number of properties (default 5), falling back to
+  the positional constructor otherwise. An explicit `@DtoMapping` attribute (`builder = AUTO | ALWAYS |
+  NEVER`) overrides the heuristic in either direction. Applies regardless of whether the target class is
+  hand-authored or foreign/generated (e.g. an OpenAPI record) - `@DtoMapping` is already declared
+  externally via `package-info.java`, not on the target class, so this was already compatible with
+  foreign target types.
+  *Inspiration: `UserService`/`User` (central-access).*
+  *Status: implemented.*
+
+- **Named mapper variants excluding nested paths, sharing one generated class**
+  Motivated by `UserService`/`User` (central-access): `CUser` -> `User` is mapped in two shapes - with
+  nested `fleets` (`findUserByGid`) and without (`findAll`, bulk listing) - to avoid an unnecessary
+  join/fetch on the common bulk-listing path. Keeps the existing "shape always derived from declaration,
+  fetch spec always wins" philosophy (rejected relaxing that rule / rejected a runtime
+  is-property-loaded auto-skip check as less deterministic). The same `(source, target)` pair can be
+  declared more than once in `package-info.java` via a named variant, e.g.
+  `@DtoMapping(source = CUser.class, target = User.class)` (base/full) plus
+  `@DtoMapping(source = CUser.class, target = User.class, name = "noFleets", exclude = "fleets")`
+  (variant). Both variants are generated into the **same** mapper class (one class per target, not one
+  per variant) and share a single private `build(source, context, boolean includeXxx, ...)` method
+  containing the common field population written once; each excluded nested path becomes a `boolean
+  includeXxx` parameter of that shared method rather than a precomputed value, so `build()` still
+  evaluates every property - included or excluded - inline, at its own declared field position (a
+  `includeFleets ? fleetsMapper.mapList(...) : List.of()` ternary in place, not hoisted out as a
+  pre-evaluated call argument). This preserves the DTO's declared property order as the true evaluation
+  order regardless of which properties a variant happens to exclude. The base `map()` passes `true` for
+  every flag; each named variant (exposed as a same-named accessor, e.g. `noFleets()`, returning a single
+  shared/cached instance of its own small `DtoMapper<SOURCE, TARGET>`-implementing inner class - not
+  reconstructed per call) passes `false` for the paths it excludes and omits that path from its own
+  `fetchGroup`. Selected via a new `query.mapTo(Class<D> dtoType, DtoMapper<T, D> mapper)` overload
+  taking an already-resolved mapper instance directly (e.g. `query.mapTo(User.class,
+  userMapper.noFleets())`) - no string-based variant lookup, and no changes needed to
+  `DtoMapperRegister`/`DtoMapperManager`.
+  *Inspiration: `UserService`/`User` (central-access).*
+  *Status: implemented.*
+
+- **Setter-based (mutable JavaBean) target construction**
+  Motivated by `EboxMapper` (central-access): its target types (`Ebox`, `MachineSummaryInfo`, from
+  `nz.co.eroad.schema.eroadtypes`, JAXB/XSD-generated legacy SOAP shapes) are plain mutable JavaBeans - a
+  public no-arg constructor plus a `void setXxx(...)` setter per property - neither a positional constructor
+  match nor a RecordBuilder-style fluent builder (see section G above). The generator currently only
+  recognizes those two construction strategies, so this common third shape (typical of JAXB/XSD-generated
+  and many hand-written mutable POJOs) can't be targeted by `@DtoMapping` at all today. Proposed: detect a
+  no-arg constructor plus a `void setXxx(propertyType)` setter per mapped property as a third construction
+  strategy, generating `Target target = new Target(); target.setX(...); ...; return target;` (mirroring the
+  existing `build = AUTO | ALWAYS | NEVER` override precedent from section G for explicit control over which
+  strategy applies). Would also unblock the `mapToBuilder()`-style "populate ignored/derived properties after
+  the generated mapping, before finishing construction" pattern for these targets (currently only available
+  for builder-shaped targets) - relevant to `EboxMapper`'s `machineSummaryInfo` (a genuinely composite,
+  multi-association derived value, out of reach of `@DtoConvert`/`@DtoPath` regardless of this gap, but a
+  natural fit for the same "map base fields via codegen, then set the derived one by hand" pattern already
+  used for `Fleet.assignedMachines`/`assignedDrivers`).
+  *Inspiration: `EboxMapper` (central-access); JAXB/XSD-generated SOAP DTO shapes generally.*
+  **Status: implemented.** `@DtoMapping(setter = AUTO | ALWAYS | NEVER)` mirrors `builder()`'s override
+  precedent. Detection requires a public no-arg constructor plus a public `setXxx(...)` setter for every
+  mapped property - either `void` or fluent-style (returning the target type itself, e.g. `public Target
+  setXxx(...) { ...; return this; }`); the generated code always calls the setter as a bare statement and
+  discards any return value, so either shape works identically. A builder, when selected, always takes
+  priority over setter-based construction. Under the default `AUTO`, setter-based construction is only
+  attempted when the target has no positional constructor matching the mapped properties (arity-based) and
+  no builder was selected - existing positional-constructor and builder-shaped targets are entirely
+  unaffected. `ALWAYS` requires the shape (codegen-time error otherwise); `NEVER` always uses a positional
+  constructor. Generated shape: `Target target = new Target(); target.setX(...); ...; return target;` (a
+  `computeIfAbsent(...)`-wrapped block-lambda variant when the target is nested elsewhere in the graph).
+  Deliberately **no** `mapToBuilder(...)`-style post-construction accessor is generated for this strategy -
+  the returned target is already the final, fully mutable instance (setters are required to be `public`), so
+  a caller can already call e.g. `dto.setExternalRef(...)` directly on the mapped result, exactly the pattern
+  `EboxMapper` already uses by hand; this is unlike the builder strategy, where the intermediate builder is
+  otherwise unreachable after its one-shot `build()` call. Test coverage:
+  `tests/test-dto-mapping/.../TestDtoSetterConstruction.java` (`ContactSetterDto`) - covers auto-detected
+  setter-chain construction plus post-construction population of two `@DtoIgnore` properties (a plain scalar
+  and a `List`) via their public setters; plus `ContactSetterFluentDto` - covers the fluent-setter-return-shape
+  variant.
+
+### H. Record entity sources
+
+- **Record-style (bare/fluent) accessors on the source (entity) side**
+  Ebean supports entity beans declared as Java `record`s (e.g. `public record CourseRecordEntity(@Id long id,
+  String name, String notes) {}` - see `test-java16`), whose only accessor shape is the bare component name
+  (`active()`, `name()`, `id()`) - never `getXxx()`/`isXxx()`. This bare-accessor convention isn't limited to
+  an actual `record` type though - an ordinary class can just as easily expose bare/fluent-style accessors
+  with no `get`/`is` prefix at all. The generator resolves the real accessor for each source type (the direct
+  source, or an intermediate `@DtoPath`/`@DtoRef` association type) by checking which shape actually exists as
+  a method, in order: (1) `isXxx()` returning `boolean` (JavaBean boolean convention), (2) `getXxx()` (JavaBean
+  convention), (3) the bare `propertyName()` itself - falling back to a guessed `getXxx()` only if none of the
+  three are found. Resolution is entirely name/existence-based (no dependency on whether the type is actually
+  a `record`). The Ebean bean-property name used in generated `FetchGroup.select(...)`/`.fetch(...)` calls is
+  tracked directly from the original property/segment name (not reverse-parsed from the resolved accessor's
+  method name), so it's correct regardless of which of the three accessor shapes was used.
+  *Inspiration: Ebean's own record-entity support (`test-java16`); user-reported gap during review.*
+  *Status: implemented.*
+
+## Rejected Requirements
+
+These were considered and explicitly rejected as out of scope:
+
+- **DTO as interface / dynamic proxy views** — Blaze `@EntityView` defines views as interfaces backed by
+  runtime proxies. This conflicts with Ebean's preference for plain, framework-unattached DTO classes.
+- **Updatable or creatable entity views (persist through DTO)** — Blaze's `@UpdatableEntityView` /
+  `@CreatableEntityView` cascade persist/update through the view. This would duplicate Ebean's existing
+  entity persistence model and introduce a second, ambiguous dirty-checking/cascade model.
+- **New predicate/filter DSL for subview collections** — Blaze allows filter expressions directly in
+  `@Mapping` (e.g. filtering a collection by an attribute value). Ebean already has typed query bean
+  predicates and `.filterMany()` for filtering child collections in queries; no new embedded filter
+  expression language is needed on the DTO itself.
+
+## References
+
+- Issue: https://github.com/ebean-orm/ebean/issues/2540
+- PR #2626: `InterceptReadOnly` / `InterceptReadWrite` split enabling the unmodifiable entity graph fast path
+- Ebean docs: https://ebean.io/docs/query/option#unmodifiable
+- QueryDSL: `@QueryProjection` (constructor-based, compile-time-checked projections)
+- Blaze-Persistence Entity Views: https://persistence.blazebit.com/documentation/1.6/entity-view/manual/en_US/

docs/guides/AGENTS.md

@@ -14,6 +14,7 @@ Key guides (fetch and follow when performing the relevant task):
 - Migrate to `Database.builder()`: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/migrating-to-database-builder.md
 - Migrate JSON APIs from Jackson core to avaje-json-core: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/migrating-json-jackson-core-to-avaje-json-core.md
 - Write queries with query beans: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/writing-ebean-query-beans.md
+- Mapping entity graphs to DTOs (`mapTo`): https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/mapping-entity-graphs-to-dtos.md
 - Derived / formula properties (`@Formula`, `@Formula2`): https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/derived-formula-properties.md
 - Persisting and transactions: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/persisting-and-transactions-with-ebean.md
 - Query metrics and naming: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/ebean-query-metrics.md

docs/guides/README.md

@@ -47,7 +47,9 @@ existing Maven project. Complete the steps in order.
 | Guide | Description |
 |-------|-------------|
 | [Write Ebean queries with query beans](writing-ebean-query-beans.md) | Step-by-step guidance for AI agents to write type-safe Ebean queries; choose the right terminal method; tune `select()` / `fetch()` / `fetchQuery()`; and project to DTOs when entity beans are not the right output |
+| [Mapping entity graphs to DTOs (`mapTo`)](mapping-entity-graphs-to-dtos.md) | Map a nested entity graph query result to a nested DTO graph via `query.mapTo(Dto.class)`; `@DtoPath`/`@DtoRef` for renamed/flattened/id-only properties; identity-aware de-dup via `DtoMapContext`; computed/aggregate DTO values via `@Entity @View` + `@Formula2`/`@Sum`/`@Aggregation`; comparison with the flat `asDto()` pipeline |
 | [Immutable bean cache for read-only references](immutable-bean-cache.md) | Use `ImmutableBeanCache` and `ImmutableBeanCaches.loading(...)` to resolve assoc-one references in read-only/unmodifiable queries, including secondary `fetchQuery`/`fetchLazy` loads |
+| [Using `RawSql` with Ebean](using-rawsql-with-ebean.md) | Choose between `RawSqlBuilder.parse()`, `unparsed()`, and `withPlaceholders()`; the `${where}`/`${andWhere}`/`${having}`/`${andHaving}` placeholder reference for CTEs, window functions, and subqueries; column mapping; and using `RawSql` with query beans |
 
 ## Persisting & transactions
 
@@ -152,6 +154,7 @@ Key guides (fetch and follow these when performing the relevant task):
 - Database configuration: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/add-ebean-postgres-database-config.md
 - Migrate to `Database.builder()`: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/migrating-to-database-builder.md
 - Write queries with query beans: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/writing-ebean-query-beans.md
+- Mapping entity graphs to DTOs (`mapTo`): https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/mapping-entity-graphs-to-dtos.md
 - Immutable bean cache for read-only references: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/immutable-bean-cache.md
 - Ebean OpenTelemetry tracing: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/add-ebean-opentelemetry.md
 - Query metrics and naming: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/ebean-query-metrics.md
@@ -181,6 +184,7 @@ Key guides (fetch and follow these when performing the relevant task):
 - Database configuration: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/add-ebean-postgres-database-config.md
 - Migrate to `Database.builder()`: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/migrating-to-database-builder.md
 - Write queries with query beans: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/writing-ebean-query-beans.md
+- Mapping entity graphs to DTOs (`mapTo`): https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/mapping-entity-graphs-to-dtos.md
 - Persisting and transactions: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/persisting-and-transactions-with-ebean.md
 - Test container setup: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/add-ebean-postgres-test-container.md
 - DB migration generation: https://raw.githubusercontent.com/ebean-orm/ebean/HEAD/docs/guides/add-ebean-db-migration-generation.md

docs/guides/add-ebean-postgres-maven-pom.md

@@ -101,7 +101,7 @@ Inside the `<dependencies>` block, add the PostgreSQL JDBC driver:
 <dependency>
     <groupId>org.postgresql</groupId>
     <artifactId>postgresql</artifactId>
-    <version>42.7.8</version>
+    <version>42.7.11</version>
 </dependency>
 ```
 

docs/guides/mapping-entity-graphs-to-dtos.md

@@ -0,0 +1,785 @@
+# Guide: Mapping entity graphs to DTOs — `query.mapTo(Dto.class)`
+
+## Purpose
+
+`query.mapTo(SomeDto.class)` maps an entity query result to a **nested DTO graph** —
+DTO fields can themselves be DTOs (`ToOne`) or `List<Dto>`/`Set<Dto>` (`ToMany`), not
+just flat scalar columns. Ebean generates the mapper (reflection-free), automatically
+derives the query's `select()`/`fetch()` spec from the target DTO's declared shape, and
+forces `setUnmodifiable(true)` so any property the mapper needs but wasn't fetched fails
+fast with `LazyInitialisationException` instead of silently lazy loading.
+
+This is distinct from the existing flat `asDto(Dto.class)` — see
+[Quick comparison](#quick-comparison-mapto-vs-asdto-vs-plain-entity-query) below.
+
+```java
+Optional<CustomerDto> dto = new QCustomer()
+  .id.eq(customerId)
+  .mapTo(CustomerDto.class)
+  .findOneOrEmpty();
+```
+
+```java
+List<CustomerDto> dtos = DB.find(Customer.class)
+  .where().eq("status", Status.ACTIVE)
+  .mapTo(CustomerDto.class)   // no .select()/.fetch() needed - derived from CustomerDto's shape
+  .findList();
+```
+
+---
+
+## Quick comparison: `mapTo()` vs `asDto()` vs plain entity query
+
+| | `mapTo(Dto.class)` | `asDto(Dto.class)` | Plain entity query |
+|---|---|---|---|
+| Shape | Nested DTO **graph** (ToOne/ToMany) | Flat, single-row DTO | Entity graph |
+| Fetch spec | Auto-derived from the DTO's declared shape | Whatever `select()`/SQL you write | Whatever `select()`/`fetch()` you write |
+| Mismatch caught | At compile time (unregistered pair fails fast at first use; codegen fails fast on structural problems) | At runtime (reflection-based constructor/setter matching) | N/A (real entity properties) |
+| Identity/de-dup | Yes - repeated source instances map to the same DTO instance (`DtoMapContext`) | N/A (one row in, one DTO out) | Yes (entity/persistence-context identity) |
+| Backing pipeline | Executes the entity ORM query, `setUnmodifiable(true)`, maps the resulting graph | Executes SQL directly against a flat `ResultSet` | Executes the entity ORM query |
+| Best for | API/read-model responses that mirror a **nested** entity shape | Flat summary rows, reports, native/vendor SQL | Data you intend to mutate and save back |
+
+See also [writing-ebean-query-beans.md](writing-ebean-query-beans.md) (Step 8/9) for
+`asDto()` and the general query-shape decision guide.
+
+---
+
+## Basic usage
+
+### 1. Declare a plain DTO
+
+DTOs are plain classes with **no framework attachment** — no annotations required for
+the common case (properties matched to the source entity by name):
+
+```java
+public class CustomerDto {
+  private final Long id;
+  private final String name;
+  private final AddressDto billingAddress;   // nested ToOne
+  private final List<ContactDto> contacts;   // nested ToMany
+
+  public CustomerDto(Long id, String name, AddressDto billingAddress, List<ContactDto> contacts) {
+    this.id = id;
+    this.name = name;
+    this.billingAddress = billingAddress;
+    this.contacts = contacts;
+  }
+
+  public Long getId() { return id; }
+  public String getName() { return name; }
+  public AddressDto getBillingAddress() { return billingAddress; }
+  public List<ContactDto> getContacts() { return contacts; }
+}
+```
+
+A constructor whose parameters match (by name) a source entity/DTO property is used
+for mapping — same shape convention as the existing `DtoQuery`. Getters are used to
+read the source's properties — a bare/fluent accessor like `active()` is resolved
+automatically too, not just `getActive()`/`isActive()` (useful both for Ebean's own
+record entity beans and for ordinary classes that just expose bare-name accessors).
+
+### 2. Register the (source, target) pair
+
+Declare each entity → DTO pair with `@DtoMapping` on a `package-info.java` (a neutral
+holder — see [Why `package-info.java`?](#why-package-infojava)):
+
+```java
+@DtoMapping(source = Customer.class, target = CustomerDto.class)
+@DtoMapping(source = Address.class, target = AddressDto.class)
+@DtoMapping(source = Contact.class, target = ContactDto.class)
+package org.example.dto;
+
+import io.ebean.annotation.DtoMapping;
+```
+
+This triggers `querybean-generator` (the existing annotation processor) to generate a
+`CustomerDtoMapper implements DtoMapper<Customer, CustomerDto>` for each pair — no new
+Maven/Gradle setup beyond what query beans already require.
+
+### 3. Query with `mapTo(...)`
+
+```java
+List<CustomerDto> dtos = DB.find(Customer.class)
+  .where().eq("status", Status.ACTIVE)
+  .mapTo(CustomerDto.class)
+  .findList();
+
+CustomerDto one = new QCustomer().id.eq(id).mapTo(CustomerDto.class).findOne();
+
+Optional<CustomerDto> maybe = new QCustomer().id.eq(id).mapTo(CustomerDto.class).findOneOrEmpty();
+```
+
+`mapTo(...)` works the same from a query bean (`QCustomer`) or a plain `DB.find(...)`/
+`ExpressionList` query.
+
+### Paging - `findPagedList()`
+
+`findPagedList()` mirrors `Query#findPagedList()` — the underlying entity query is paged
+as normal and each page's result is mapped to the target DTO list:
+
+```java
+PagedList<CustomerDto> paged = DB.find(Customer.class)
+  .where().eq("status", Status.ACTIVE)
+  .orderBy().asc("name")
+  .setFirstRow(0)
+  .setMaxRows(50)
+  .mapTo(CustomerDto.class)
+  .findPagedList();
+
+int totalRowCount = paged.getTotalCount();      // page metadata - unaffected by DTO mapping
+List<CustomerDto> page1 = paged.getList();       // mapped DTOs for this page
+```
+
+Page metadata (`getTotalCount()`, `getTotalPageCount()`, `hasNext()`, `hasPrev()`,
+`loadCount()`, ...) reflects the underlying entity query directly; only `getList()`
+is mapped (once, cached) to the DTO type.
+
+### An unregistered pair fails fast
+
+If `(Customer.class, SomeDto.class)` was never declared via `@DtoMapping`, the first
+`mapTo(SomeDto.class)` call throws immediately:
+
+```
+PersistenceException: No DtoMapper registered mapping Customer -> SomeDto
+  - check @DtoMapping(source = Customer.class, target = SomeDto.class) is declared
+    on a package-info.java processed by querybean-generator
+```
+
+---
+
+## Auto-derived fetch spec
+
+You never write `.select()`/`.fetch()` for a `mapTo(...)` query — the generated mapper
+exposes a `fetchGroup()` built directly from the DTO's declared shape, and `mapTo(...)`
+applies it automatically:
+
+```java
+public CustomerDtoMapper() {
+  this(new AddressDtoMapper(), new ContactDtoMapper());
+}
+
+public CustomerDtoMapper(DtoMapper<Address, AddressDto> billingAddressMapper,
+                          DtoMapper<Contact, ContactDto> contactsMapper) {
+  this.fetchGroup = FetchGroup.of(Customer.class)
+    .select("id,name")
+    .fetch("billingAddress", billingAddressMapper.fetchGroup())
+    .fetch("contacts", contactsMapper.fetchGroup())
+    .build();
+}
+```
+
+Each nested DTO gets its own generated mapper (mirroring MapStruct's per-type mapper
+generation), wired together via constructor injection — mappers are stateless and
+substitutable, not static singletons. Mapper instances are constructed once, in
+dependency order, and reused — see [DtoMapperManager](#one-mapper-instance-per-pair)
+below.
+
+---
+
+## Nested collections and identity-aware de-duplication
+
+When the same source entity instance is reachable via more than one path in the graph
+(e.g. two `Contact`s sharing the same `Customer`, or the same `Address` referenced from
+two paths), the mapper reuses the **same** target DTO instance rather than creating
+duplicate-but-equal copies — mirroring the identity semantics the entity graph already
+has:
+
+```java
+List<CustomerDto> dtos = DB.find(Customer.class).mapTo(CustomerDto.class).findList();
+
+CustomerDto customer = dtos.get(0);
+// both contacts share the exact same customer.billingAddress AddressDto instance
+assertThat(customer.getContacts().get(0).getCustomer())
+  .isSameAs(customer.getContacts().get(1).getCustomer());
+```
+
+This is done via a `DtoMapContext` threaded through every nested `map(...)` call within
+one top-level `mapList(...)`/`findList()` invocation. The generated code only pays for
+this when it can actually matter — a DTO that's never nested under another DTO skips
+`DtoMapContext` entirely (there's nothing else in scope to de-duplicate against):
+
+```java
+// AddressDto is nested under CustomerDto (reachable via multiple contacts) - dedup needed
+// dedup using DtoMapContext, same Address instance can be reached via more than one path in the graph
+return context.computeIfAbsent(AddressDto.class, source, s -> new AddressDto(...));
+
+// ContactSummaryDto is only ever mapped as a top-level query result - no dedup possible
+// skip DtoMapContext, only ever a top-level mapping
+return new ContactSummaryDto(source.getId(), source.getFullName());
+
+// CustomerDto has nested mappers (billingAddress, contacts) but is never itself nested
+// DtoMapContext for nested mappers only
+return new CustomerDto(source.getId(), source.getName(), ...);
+```
+
+The generated comment tells you at a glance which of the three cases applies — useful
+when debugging why a `DtoMapContext` is (or isn't) in the generated code for a
+particular mapper.
+
+---
+
+## Using generated mappers directly (outside `query.mapTo()`)
+
+Every generated `XxxDtoMapper` is a plain public class — you don't need `ServiceLoader`,
+a registry, or a `Database` just to construct or call one directly (though
+`DtoMapperManager`, below, is available if you want a shared, DI-friendly lookup). It
+always has a public no-arg constructor (delegating to defaults for any nested mappers/
+`@DtoConvert` converters) plus an explicit constructor taking those dependencies directly,
+and implements `DtoMapper<SOURCE, TARGET>`'s `map(...)`/`mapList(...)`:
+
+```java
+CustomerDtoMapper mapper = new CustomerDtoMapper();
+CustomerDto dto = mapper.map(customer);       // any Customer you already have on hand
+List<CustomerDto> dtos = mapper.mapList(customers);
+```
+
+This works on **any** entity graph, not just one that just came out of a `mapTo(...)`
+query — e.g. entities you loaded with a plain `.fetch(...)` query, entities you just
+`.save()`d, or entities built by hand in a test. The only requirement is that whatever the
+mapper reads (via plain getters) is actually populated — there's no lazy-loading fallback.
+
+### Testing the mapping in isolation
+
+Because mappers are plain, constructor-injected classes, you can unit test the mapping
+logic itself — independent of `query.mapTo()`, the DTO-pair registry, and (for
+`@DtoConvert` instance-dispatch converters) `DtoConverterManager` — by passing a test
+double straight into the explicit constructor:
+
+```java
+SecretCipher upperCasingTestCipher = String::toUpperCase;
+ContactConversionDto dto = new ContactConversionDtoMapper(upperCasingTestCipher).map(contact);
+
+assertThat(dto.getSecretCode()).isEqualTo("SHH");
+```
+
+No `DtoConverterManager.put(...)` registration needed for this kind of test — the real
+production wiring (`DtoConverterManager.get(SecretCipher.class)`) only happens in the
+generated no-arg constructor, which the explicit-constructor call above bypasses entirely.
+See `TestCustomerDtoGraphMapping` (mapper called directly against a manually queried
+graph) and `TestMapperManualUsage` (mapper called directly against hand-built/just-saved
+entities, plus the converter test-double case above) in `tests/test-dto-mapping`.
+
+### `DtoMapperManager` — resolving a generated mapper for dependency injection
+
+`new CustomerDtoMapper()` is enough for a single mapper, but if your application wants a
+single shared instance of *every* generated mapper (mirroring how `query.mapTo()` resolves
+them internally) - e.g. to wire one up for constructor injection into a service, replacing
+a hand-written mapper class - use `io.ebean.DtoMapperManager`:
+
+```java
+DtoMapperManager manager = new DtoMapperManager();   // ServiceLoader discovery only - no Database needed
+CustomerDtoMapper mapper = manager.get(CustomerDtoMapper.class);
+```
+
+`DtoMapperManager` has no dependency on `Database` at all - its constructor only does
+`ServiceLoader.load(DtoMapperRegister.class)` - so it can be constructed independently,
+before (or entirely without) a `Database`, e.g. as a bean in an avaje-inject (or any DI
+framework's) dependency graph:
+
+```java
+@Factory
+class DtoMapperFactory {
+
+  @Bean
+  DtoMapperManager dtoMapperManager() {
+    return new DtoMapperManager();
+  }
+
+  @Bean
+  CustomerDtoMapper customerDtoMapper(DtoMapperManager manager) {
+    return manager.get(CustomerDtoMapper.class);
+  }
+}
+```
+
+If you also want `query.mapTo(...)` to use that *exact same* manager instance (so there's
+only ever one instance of each generated mapper, whichever path resolves it), register it
+via `DatabaseBuilder.putServiceObject` before building the `Database` - this is the same
+`putServiceObject`/`getServiceObject` mechanism already used for things like
+`AutoMigrationRunner`:
+
+```java
+DtoMapperManager sharedManager = new DtoMapperManager();
+
+Database db = Database.builder()
+  .putServiceObject(DtoMapperManager.class, sharedManager)
+  .build();
+
+// query.mapTo(...) against `db` now resolves mappers via `sharedManager`
+```
+
+If nothing is registered via `putServiceObject`, the `Database` builds its own default
+`DtoMapperManager` instance instead - registering one is entirely optional. A standalone
+`DtoMapperManager()` construction bypasses the `DatabaseConfigProvider` hook (that hook is
+specifically about `Database` startup ordering), so if any of your mappers need a
+`@DtoConvert` instance-dispatch converter, register it via `DtoConverterManager.put(...)`
+yourself first, exactly as you would before building a `Database`. See
+`TestDtoMapperManager` and `TestDtoMapperManagerSharing` in `tests/test-dto-mapping`.
+
+### Recipe: adding extra caller-supplied fields after mapping
+
+Sometimes a target DTO needs a field that isn't sourced from the entity graph at all - e.g.
+populated from a separate query or business rule, only when a caller-supplied flag is set.
+Rather than the generator supporting partial/builder-based mapping directly, if your DTO is
+a record with a "seed from instance" builder (e.g. via `avaje-recordbuilder`'s
+`@RecordBuilder`, which generates `Target.builder(existingInstance)`), just map the
+graph-sourced fields as usual and layer the extra field on afterwards:
+
+```java
+Driver base = mapper.map(cDriver);
+Driver full = DriverBuilder.builder(base).fleets(fleets).build();
+```
+
+No generator changes needed - the mapped instance is simply the seed for the builder.
+
+---
+
+## Large targets: builder-based construction and named variants
+
+Two features aimed at large, builder-shaped target DTOs (typically OpenAPI-generated records
+with a generated builder), where a positional constructor call is unwieldy and a single query
+needs to populate the target in more than one shape.
+
+### Builder-based construction (`builder = AUTO | ALWAYS | NEVER`)
+
+If the target has a static no-arg `Target.builder()` factory returning a type with a fluent
+(returns-itself) setter per property plus a `build()` method - the shape
+`avaje-recordbuilder`'s `@RecordBuilder` generates - the generated mapper can construct the
+target via `Target.builder().prop(x)....build()` instead of `new Target(a, b, c, ...)`:
+
+```java
+public record User(Long id, String name, String email, /* ... 21 more fields */) {
+
+  public static UserBuilder builder() {
+    return UserBuilder.builder();
+  }
+}
+```
+
+```java
+@DtoMapping(source = CUser.class, target = User.class)
+package org.example.dto;
+```
+
+By default (`builder = AUTO`), the generator auto-detects a matching builder and uses it only
+once the target has more than 5 properties, falling back to a positional constructor for
+smaller DTOs. Override explicitly either direction:
+
+```java
+@DtoMapping(source = CUser.class, target = User.class, builder = DtoMapping.Builder.ALWAYS)
+```
+
+`builder = ALWAYS` is a codegen-time error if no matching builder shape is found; `builder =
+NEVER` always uses a positional constructor even if a builder is detected. This applies
+regardless of whether the target is hand-authored or foreign/generated - `@DtoMapping` is
+already declared externally via `package-info.java`, so no annotation on the target itself is
+needed either way.
+
+### Named variants excluding nested paths (`name=`, `exclude=`)
+
+The same `(source, target)` pair can be registered more than once - one base mapping (leaving
+`name()` empty) plus any number of named variants, each excluding one or more nested
+ToOne/ToMany properties:
+
+```java
+@DtoMapping(source = CUser.class, target = User.class)
+@DtoMapping(source = CUser.class, target = User.class, name = "noFleets", exclude = "fleets")
+package org.example.dto;
+```
+
+Both variants are generated into the **same** mapper class (one class per target, not one per
+variant) - the generated `noFleets()` accessor returns a single shared/cached `DtoMapper<CUser,
+User>` view (not reconstructed per call), omitting `fleets` from both its mapped output (`null`
+for a ToOne, `List.of()` for a ToMany) and its own `fetchGroup()`. Each excluded property is still
+evaluated inline at its own declared field position internally (guarded by a boolean flag) - a
+variant's exclusions never change the evaluation order of the DTO's other properties. Select it
+with the `query.mapTo(Class, DtoMapper)` overload, which takes an already-resolved mapper instance
+directly - no string-based lookup:
+
+```java
+UserMapper userMapper = new UserMapper();
+
+// full shape, with fleets fetched/mapped
+List<User> withFleets = DB.find(CUser.class)
+  .mapTo(User.class, userMapper) // or plain .mapTo(User.class)
+  .findList();
+
+// bulk listing shape - fleets excluded from both the fetch spec and the output
+List<User> noFleets = DB.find(CUser.class)
+  .mapTo(User.class, userMapper.noFleets())
+  .findList();
+```
+
+Only nested ToOne/ToMany properties can be excluded - a scalar or `@DtoRef` property can't be,
+since there's no type-safe "absent" value for an arbitrary scalar type. Named variants are
+scoped to independent, top-level query results only - unlike the base mapping, they don't
+participate in `DtoMapContext` identity de-duplication when nested elsewhere in a graph, since a
+variant is never intended to be nested inside another DTO's mapping.
+
+---
+
+## `@DtoPath` — renamed or flattened properties
+
+By default a DTO property is matched to the source entity property (or nested DTO
+mapper) of the **same name**. `@DtoPath` overrides that, allowing a DTO property to be
+renamed and/or flattened from a nested path using dot-notation:
+
+```java
+public class ContactDto {
+  private final long id;
+  private final String firstName;
+  private final String lastName;
+
+  @DtoPath("customer.billingAddress.city")
+  private final String customerCity;   // flattened, 2 hops through customer
+
+  // constructor / getters ...
+}
+```
+
+The generated mapper reads the path with a null-guard at each hop and adds the
+necessary joins to the fetch spec automatically:
+
+```java
+(s.getCustomer() == null ? null
+  : (s.getCustomer().getBillingAddress() == null ? null
+      : s.getCustomer().getBillingAddress().getCity()))
+```
+
+`@DtoPath` is purely a compile-time/codegen-time hint — the DTO class itself carries no
+runtime dependency on the annotation.
+
+### Fetch-path collisions are a compile-time error
+
+A `@DtoPath` whose fetch path is identical to a nested `ToOne`/`ToMany` property's own
+fetch path on the *same* DTO (e.g. a nested `customer` field alongside
+`@DtoPath("customer.name")` — both resolve to fetch path `"customer"`) fails the build
+with a clear error, rather than silently discarding one side's fetched properties:
+
+```
+error: @DtoPath property 'customerName' on FooDto resolves to fetch path 'customer',
+  which collides with the nested mapping already using that same fetch path - Ebean's
+  fetch spec can only carry one set of properties per path, so one silently discards
+  the other. Move 'customerName' onto the nested DTO type instead, or choose a
+  @DtoPath that reaches into a different, non-colliding path.
+```
+
+Fix it either way it suggests: move the property onto the nested DTO type, or choose a
+`@DtoPath` that reaches a different path (as `customerCity` above does deliberately,
+using a 3-segment path through `customer.billingAddress` rather than colliding with a
+plain `customer` nested field).
+
+---
+
+## `@DtoRef` — id-only back-references (breaking cycles)
+
+The DTO graph derived from a set of DTO types must form a DAG — codegen fails if it
+doesn't. `@DtoRef` is the explicit escape hatch for an intentional back-reference, e.g.
+a `Contact` DTO referencing its parent `Customer` by id only, rather than re-embedding
+a full `CustomerDto` (which would recreate the `Customer → Contact → Customer` cycle):
+
+```java
+public class ContactDto {
+  private final long id;
+
+  @DtoRef
+  private final Long customerId;   // id-only, no nested CustomerDto re-embedded
+
+  // constructor / getters ...
+}
+```
+
+The generated fetch spec adds the association to the **root** `select(...)` rather
+than a nested `.fetch(...)` — this reads the foreign-key column directly off the base
+table (no SQL join):
+
+```java
+this.fetchGroup = FetchGroup.of(ContactStats.class)
+  .select("customer,contactCount,engagementScore")   // "customer" -> FK column, no join
+  .build();
+```
+
+```java
+(source.getCustomer() == null ? null : source.getCustomer().getId())
+```
+
+If the same association is *also* independently nested-fetched elsewhere on the DTO
+(e.g. `ContactDto` has both a nested `customer` field **and** `@DtoRef Long
+customerId`), the generator recognizes the association is already covered and doesn't
+add a redundant/duplicate select — no join is added twice.
+
+---
+
+## `@DtoConvert` — custom property conversion
+
+Some properties need more than a plain getter copy — a scalar coercion (`short` to
+`boolean`), an enum-to-`String` mapping, or a conversion needing a real dependency (e.g.
+decrypting a value with a cipher). `@DtoConvert(value = ConverterType.class, method =
+"name")` covers both, combinable with `@DtoPath` when the source value also needs a
+path/rename override:
+
+```java
+public class ContactDto {
+  @DtoPath("status")
+  @DtoConvert(value = ContactConversions.class, method = "toActive")
+  private final boolean active;             // Contact.status (Short) -> boolean
+
+  @DtoConvert(value = SecretCipher.class, method = "decode")
+  private final String secretCode;          // decrypted via a registered SecretCipher
+
+  // constructor / getters ...
+}
+```
+
+The generator resolves the referenced method at codegen time and dispatches one of two
+ways, purely based on whether it's `static`:
+
+- **Static method** — inlined as a direct static call
+  (`ContactConversions.toActive(source.getStatus())`). No registration needed at all —
+  use this for common, reusable, dependency-free coercions.
+- **Instance method** — the generated mapper resolves one shared instance via
+  `DtoConverterManager.get(SecretCipher.class)`, wired as a constructor
+  parameter/field (the same shape as nested-mapper constructor injection), then calls
+  `secretCipher.decode(source.getSecretCode())`. Use this when the conversion needs a
+  real dependency.
+
+### Registering an instance-dispatch converter
+
+`DtoConverterManager` is a small, deliberately-scoped static put/get bridge — register
+an already-constructed converter instance (e.g. built by your DI container) **before**
+building the `Database`:
+
+```java
+AES256Cipher cipher = ...;                                    // already DI-constructed
+DtoConverterManager.put(SecretCipher.class, cipher::decrypt); // or a small adapter class
+
+Database db = DatabaseFactory.create(...); // generated mappers resolve converters from here
+```
+
+If nothing is registered for a required type, `DtoConverterManager.get(...)` throws a
+`PersistenceException` immediately — this happens as an eager field initializer on the
+generated `EbeanDtoMapperRegister`, so a missing registration fails fast at `Database`
+build time, not lazily on first `mapTo(...)` call.
+
+> **Testing tip:** since `EbeanDtoMapperRegister`'s mapper fields are all constructed
+> together when the `Database` starts, register converters via a `DatabaseConfigProvider`
+> (a `ServiceLoader` hook that runs before the `Database` is built) rather than a test
+> `@BeforeAll`, so registration always happens before *any* test triggers startup —
+> regardless of which test class runs first.
+
+## `@DtoMixin` — overlaying annotations onto a DTO you can't edit
+
+Some DTOs are generated elsewhere (e.g. from an OpenAPI spec, regenerated on every
+build) and can't be annotated directly. `@DtoMixin(Target.class)` overlays
+`@DtoPath`/`@DtoRef`/`@DtoConvert` from a separate companion type instead — directly
+mirroring avaje-jsonb's `@Json.MixIn` mechanism. Declare a companion interface (or
+class) whose method names match the target DTO's property names:
+
+```java
+// ContactMixinDto itself carries no Ebean annotations at all
+public class ContactMixinDto {
+  public ContactMixinDto(long id, String firstName, boolean active, String secretCode) { ... }
+  // getters ...
+}
+
+@DtoMixin(ContactMixinDto.class)
+interface ContactMixinDtoMixin {
+
+  @DtoPath("status")
+  @DtoConvert(value = ContactConversions.class, method = "toActive")
+  boolean active();
+
+  @DtoConvert(value = SecretCipher.class, method = "decode")
+  String secretCode();
+}
+```
+
+The processor matches each mixin method to the target's property by name and applies
+whichever annotations are present as if they were declared on the target field itself.
+The mixin type is never instantiated and carries no runtime footprint — it's purely a
+compile-time/codegen-time hint.
+
+---
+
+## Computed / aggregate properties via `@Entity @View`
+
+There's no dedicated "formula on DTO" annotation (a narrower `@Formula2`-on-DTO
+variant was explored and rejected — see
+[dto-mapping-design.md](../dto-mapping-design.md) for the reasoning). Instead, model
+the computed value as its own read-only entity using `@View`, then map that entity to a
+plain DTO with the same `@DtoMapping` machinery described above. `@View(name = "...")`
+here just points a second entity at an **existing** table — it does not create a new
+database view or table.
+
+### Worked example — computed column (`@Formula2`)
+
+```java
+@Entity
+@View(name = "contact")   // reads the existing 'contact' table, no new DDL
+public class ContactSummary {
+  @Id
+  private Long id;
+  private String firstName;
+  private String lastName;
+
+  @Formula2("concat(firstName, ' ', lastName)")
+  private String fullName;
+
+  // getters ...
+}
+```
+
+```java
+public class ContactSummaryDto {
+  private final Long id;
+  private final String fullName;
+  // constructor / getters ...
+}
+```
+
+```java
+@DtoMapping(source = ContactSummary.class, target = ContactSummaryDto.class)
+```
+
+```java
+List<ContactSummaryDto> summaries = DB.find(ContactSummary.class)
+  .mapTo(ContactSummaryDto.class)
+  .findList();
+```
+
+### Worked example — group-by aggregation (`@Sum`/`@Aggregation`)
+
+The same `@View`-on-base-table pattern applies to Ebean's `@Sum`/`@Aggregation`
+group-by formulas — the Blaze-Persistence parallel is an `@EntityView` with
+`@Mapping("SIZE(...)")`/`@Mapping("SUM(...)")` correlated mappings:
+
+```java
+@Entity
+@View(name = "contact")
+public class ContactStats {
+  @Id
+  private Long id;              // required so @Aggregation("count(id)") has something to
+                                 // count; deliberately never selected/mapped - selecting it
+                                 // would defeat the aggregation (one row per contact
+                                 // instead of one row per customer)
+  @ManyToOne
+  private Customer customer;
+
+  @Aggregation("count(id)")
+  private Long contactCount;
+
+  @Sum
+  private Integer engagementScore;
+
+  // getters ...
+}
+```
+
+```java
+public class ContactStatsDto {
+  @DtoRef
+  private final Long customerId;   // also the implicit GROUP BY key
+  private final Long contactCount;
+  private final Integer engagementScore;
+  // constructor / getters ...
+}
+```
+
+Because `customerId` uses `@DtoRef`, the generated fetch spec is
+`select("customer,contactCount,engagementScore")` with **no join** — the query groups
+by the FK column directly:
+
+```sql
+select t0.customer_id, count(t0.id), sum(t0.engagement_score)
+from contact t0
+group by t0.customer_id
+```
+
+---
+
+## Performance notes
+
+### Fail-fast, no accidental lazy loading
+
+`mapTo(...)` forces `query.setUnmodifiable(true)` under the hood. If the mapper ever
+needs a property that wasn't fetched, it throws `LazyInitialisationException`
+immediately rather than silently issuing an extra query per row or returning `null`.
+`InterceptReadOnly` (the unmodifiable-graph bean state) is also cheap — a `boolean[]
+loaded` flag array plus a `frozen` flag, not a full second copy of bean state.
+
+### One mapper instance per pair
+
+Generated mappers are constructed once (in dependency order — a mapper with nested
+mappers takes them as constructor params) and reused across every `mapTo(...)` call for
+that pair, resolved and cached by `DtoMapperManager` keyed on `(sourceType, dtoType)`.
+
+### `DtoMapContext` overhead only where it earns its keep
+
+As shown above, the generator only involves `DtoMapContext` for mappers that can
+actually be reached via more than one path in some graph (dedup) or that have nested
+mappers of their own (need to thread the context down); a DTO that's only ever a
+top-level query result skips it entirely.
+
+### Fetch strategy and pagination carry over unchanged
+
+Existing fetch-strategy control (`+query`/`+lazy`, `fetchQuery()`) and pagination
+(including keyset pagination and `findPagedList()`) work the same whether the query
+target is an entity graph or a `mapTo(...)` DTO graph — no special-casing needed.
+
+---
+
+## Which should I use?
+
+- **`mapTo(Dto.class)`** — the target is a **nested** shape (has its own ToOne/ToMany
+  DTO fields) that should mirror part of the entity graph; you want the fetch spec
+  derived automatically and verified to match the DTO's declared shape.
+- **`asDto(Dto.class)`** / `DB.findDto(...)` — the target is a **flat** row (report,
+  summary, native/vendor SQL); you're comfortable with runtime-checked column-to-bean
+  matching, or the SQL doesn't map cleanly to entity property paths at all.
+- **Plain entity query** — the caller needs a real, persistable, mutable entity — not a
+  read-only projection.
+
+---
+
+## Reference
+
+### Why `package-info.java`?
+
+`@DtoMapping` is declared on a package (`ElementType.PACKAGE`), not the DTO or the
+entity, because:
+- the DTO type is often owned/generated elsewhere (e.g. from an OpenAPI spec) and
+  shouldn't need to be annotated with an internal persistence/entity type;
+- one entity may be the source for several different DTOs (e.g. a summary vs. a detail
+  view), and the same entity/DTO pair may need registering from multiple consuming
+  modules.
+
+### Annotations at a glance
+
+| Annotation | Target | Purpose |
+|---|---|---|
+| `@DtoMapping(source=, target=)` | `package-info.java` | Registers an entity → DTO pair, triggers mapper generation |
+| `@DtoMapping(..., builder=)` | `package-info.java` | `AUTO` (default, threshold-based) / `ALWAYS` / `NEVER` - builder-chain vs positional constructor |
+| `@DtoMapping(..., name=, exclude=)` | `package-info.java` | Registers a named variant sharing the base mapping's generated class, excluding nested paths |
+| `@DtoPath("a.b.c")` | DTO field/getter | Renamed and/or flattened multi-hop property mapping |
+| `@DtoRef` | DTO field/getter | Id-only back-reference; breaks a cycle; root-selects the FK (no join) |
+| `@DtoConvert(value=, method=)` | DTO field/getter | Custom scalar conversion - static (no registration) or instance (via `DtoConverterManager`) dispatch |
+| `@DtoMixin(Target.class)` | Companion interface/class | Overlays `@DtoPath`/`@DtoRef`/`@DtoConvert` onto a DTO that can't be annotated directly |
+
+### Parallels with other tools
+
+If you're coming from another mapping library, here's the rough correspondence:
+
+| Ebean | MapStruct | Blaze-Persistence |
+|---|---|---|
+| Generated `DtoMapper` per (source, DTO) pair | Generated `@Mapper` implementation | `@EntityView` (interface + runtime proxy) |
+| `@DtoPath("a.b.c")` | `@Mapping(target = "x", source = "a.b.c")` | `@Mapping("a.b.c")` |
+| `@DtoRef` | `@Context`/manual cycle-breaking (no dedicated annotation) | Sub-view referencing an id-only projection |
+| `@DtoConvert(value=, method=)` | `@Mapping(qualifiedByName = "...")` / custom mapper methods | Custom converter/`@Mapping` expression |
+| `@DtoMixin(Target.class)` | N/A (annotate the `@Mapper` interface's abstract methods instead) | N/A |
+| `DtoMapContext` identity de-dup | Not built in (opt-in `@MappingTarget`/manual caching) | Built in (entity-view identity) |
+| `@Entity @View` + `@Formula2`/`@Sum`/`@Aggregation` for computed DTO values | N/A (MapStruct doesn't touch SQL) | `@Mapping("SIZE(...)")` / `@Mapping("SUM(...)")` correlated mappings |
+
+See [dto-mapping-design.md](../dto-mapping-design.md) for the full design rationale and
+[dto-mapping-requirements.md](../dto-mapping-requirements.md) for the accepted/rejected
+requirements this feature was scoped against (issue
+[#2540](https://github.com/ebean-orm/ebean/issues/2540)).

docs/guides/using-rawsql-with-ebean.md

@@ -0,0 +1,464 @@
+# Guide: Using `RawSql` with Ebean
+
+## Purpose
+
+`RawSql` lets you back an Ebean bean with a **hand-written SQL query** instead of
+Ebean generating the SQL from the entity mapping. Ebean still handles object
+mapping (result set columns → bean properties), lazy loading of associated beans,
+and - depending on how the `RawSql` is built - dynamic `WHERE`/`HAVING` predicates
+added through the normal query API.
+
+Use this guide when you need to:
+
+- run vendor-specific SQL, complex aggregation, or reporting queries that don't
+  map cleanly to an ORM query
+- reuse a hand-tuned query but still want typed/dynamic predicates, paging, or
+  `ORDER BY` added by the caller
+- back a query bean (`Q*`) or DTO-like bean with SQL containing a CTE, window
+  function, or subquery in the `FROM` clause
+
+Prefer ordinary query bean queries first - see
+[Write Ebean queries with query beans](writing-ebean-query-beans.md), Step 9,
+for the full decision order (query bean → `asDto()` → DTO query → raw SQL).
+This guide covers raw SQL once you've decided it's the right tool.
+
+---
+
+## The bean behind a `RawSql` query
+
+A bean queried with `RawSql` is not necessarily backed by a physical table. Annotate
+it `@Entity @Sql` to tell Ebean it is mapped via `RawSql` rather than table DDL:
+
+```java
+@Entity
+@Sql
+public class OrderAggregate {
+
+  @OneToOne
+  Order order;
+
+  Double totalAmount;
+  Long totalItems;
+
+  // getters/setters
+}
+```
+
+`@Sql` beans still get a generated query bean (`QOrderAggregate`) if the
+querybean-generator annotation processor is configured - see
+[Using `RawSql` with query beans](#using-rawsql-with-query-beans) below.
+
+You can also query an ordinary table-backed `@Entity` with `RawSql` - the column
+mapping just needs to line up with that entity's properties.
+
+---
+
+## Building a `RawSql` - three factory methods
+
+`RawSqlBuilder` has three ways to construct a `RawSql`, depending on how much of
+the SQL Ebean needs to understand:
+
+| Method | SELECT columns parsed? | Dynamic WHERE/HAVING/ORDER BY? | Use for |
+|--------|------------------------|------------------------|---------|
+| `RawSqlBuilder.parse(sql)` | Yes | Yes | Ordinary `SELECT ... FROM ... WHERE ...` statements |
+| `RawSqlBuilder.unparsed(sql)` | No | No | Fixed SQL that never needs additional predicates |
+| `RawSqlBuilder.withPlaceholders(sql)` | No (explicit `columnMapping()` required) | Yes, via `${where}` / `${andWhere}` / `${having}` / `${andHaving}` / `${orderBy}` / `${andOrderBy}` | CTEs, window functions, subqueries - SQL that keyword-based parsing can't handle |
+
+### `parse(sql)` - the common case
+
+`parse(sql)` scans the SQL text for the `select` / `from` / `where` / `group by`
+/ `having` / `order by` keywords to work out the SELECT column list (so it can
+validate your column mappings) and the injection points for dynamic `WHERE`/
+`HAVING` expressions.
+
+```java
+RawSql rawSql = RawSqlBuilder.parse(
+    "select c.id, c.name, c.status from customer c")
+  .columnMapping("c.id", "id")
+  .columnMapping("c.name", "name")
+  .columnMapping("c.status", "status")
+  .create();
+
+List<Customer> customers = DB.find(Customer.class)
+  .setRawSql(rawSql)
+  .where().eq("status", Customer.Status.ACTIVE)
+  .orderBy("name")
+  .findList();
+```
+
+Because the SQL is parsed, mistakes in `columnMapping()` (unknown column, wrong
+order for `unparsed`-style mappings) are caught early. **This fails on SQL the
+keyword parser can't make sense of** - a `WITH` CTE, a window function, a
+subquery in `FROM`, etc. - because the keyword positions found don't correspond
+to the outer query's real structure. Use `withPlaceholders(sql)` for that SQL
+instead (see below).
+
+### `unparsed(sql)` - fixed queries
+
+`unparsed(sql)` skips all parsing. The SQL is used exactly as written, and **no
+further `WHERE`/`HAVING`/`ORDER BY` can be added** by the caller - useful for a
+completely fixed reporting query with no caller-supplied filtering.
+
+```java
+RawSql rawSql = RawSqlBuilder.unparsed(
+    "select id, name, status from customer where status = 'ACTIVE'")
+  .columnMapping("id", "id")
+  .columnMapping("name", "name")
+  .columnMapping("status", "status")
+  .create();
+
+List<Customer> customers = DB.find(Customer.class)
+  .setRawSql(rawSql)
+  .findList();
+```
+
+Column mappings for `unparsed(sql)` must be supplied **in the same order** as
+the columns appear in the SQL, since there's no parsing to match them by name.
+
+### `withPlaceholders(sql)` - complex SQL (CTEs, window functions, subqueries)
+
+`withPlaceholders(sql)` avoids keyword scanning entirely. You mark exactly where
+a dynamic `WHERE`/`HAVING`/`ORDER BY` expression should be injected using
+placeholder tokens, and column mappings are always explicit (as with `unparsed`).
+
+#### Placeholder reference
+
+| Placeholder | Meaning | Use when |
+|-------------|---------|----------|
+| `${where}` | Insert a new `WHERE <expr>` clause here | No static `WHERE` clause exists yet at this point in the SQL |
+| `${andWhere}` | Insert `AND <expr>` here | A static `WHERE ...` clause already exists in the SQL and you want to append to it |
+| `${having}` | Insert a new `HAVING <expr>` clause here | No static `HAVING` clause exists yet at this point in the SQL |
+| `${andHaving}` | Insert `AND <expr>` here | A static `HAVING ...` clause already exists in the SQL and you want to append to it |
+| `${orderBy}` | Insert a new `ORDER BY <expr>` clause here | No static `ORDER BY` clause exists yet at this point in the SQL, and callers may supply `.orderBy(...)` |
+| `${andOrderBy}` | Insert `, <expr>` here | A static `ORDER BY ...` clause already exists in the SQL and you want callers to be able to append extra sort columns to it |
+
+Rules:
+
+- At least one placeholder is required - `withPlaceholders(sql)` throws
+  `IllegalArgumentException` if none of the six tokens are present.
+- Use only the placeholders you need. Omit `${where}`/`${andWhere}` entirely if
+  the query never needs a dynamic `WHERE` (e.g. only a dynamic `HAVING` on an
+  aggregate). Omit `${having}`/`${andHaving}` if there's no dynamic `HAVING`.
+  Omit `${orderBy}`/`${andOrderBy}` if the ordering is always fixed.
+- Explicit `columnMapping()` is required for every returned column - there is no
+  column-list parsing to infer names from.
+- **A caller-supplied `.orderBy(...)`/`.order(...)` is only applied if the SQL
+  contains an `${orderBy}` or `${andOrderBy}` placeholder.** Without one of
+  those placeholders there is no defined injection point for dynamic ordering,
+  so any `.orderBy(...)` call on the query is safely ignored rather than risk
+  producing invalid SQL - even if the template has a static trailing
+  `ORDER BY ...` of its own. If you need callers to be able to influence
+  ordering, add `${orderBy}` (no existing static order by) or `${andOrderBy}`
+  (append after an existing static order by).
+- Any other static SQL that follows a `${where}`/`${having}` placeholder (e.g.
+  a trailing `GROUP BY`) is preserved and correctly positioned **after**
+  whatever dynamic expression gets injected at that placeholder.
+
+#### Example - CTE with `${where}`
+
+```java
+String sql = """
+  with order_totals as (
+    select o.id as order_id, sum(d.qty * d.unit_price) as total_amount
+    from o_order o
+    join o_order_detail d on d.order_id = o.id
+    group by o.id
+  )
+  select order_id, total_amount
+  from order_totals
+  ${where}
+  order by order_id
+  """;
+
+RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+  .columnMapping("order_id", "order.id")
+  .columnMapping("total_amount", "totalAmount")
+  .create();
+
+List<OrderAggregate> list = DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)
+  .where().gt("totalAmount", 100)
+  .findList();
+```
+
+`total_amount` is a genuine column of the `order_totals` CTE here, so it's valid
+to filter on it in the outer `WHERE` - this only works because the aggregate is
+computed inside the CTE rather than as a same-level `SELECT` alias.
+
+#### Example - static `WHERE` already present, append with `${andWhere}`
+
+```java
+String sql = "... from order_totals where total_amount > 0 ${andWhere} order by order_id";
+
+RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+  .columnMapping("order_id", "order.id")
+  .columnMapping("total_amount", "totalAmount")
+  .create();
+
+// executed SQL: ... where total_amount > 0 and total_amount > ? order by order_id
+DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)
+  .where().gt("totalAmount", 100)
+  .findList();
+```
+
+#### Example - `${having}` only, filtering on an aggregate directly
+
+No `WHERE` placeholder is needed if you only ever filter on the aggregate value:
+
+```java
+String sql =
+  "select o.id as order_id, sum(d.qty * d.unit_price) as total_amount" +
+  " from o_order o join o_order_detail d on d.order_id = o.id" +
+  " group by o.id" +
+  " ${having}" +
+  " order by order_id";
+
+RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+  .columnMapping("order_id", "order.id")
+  .columnMapping("total_amount", "totalAmount")
+  .create();
+
+List<OrderAggregate> list = DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)
+  .having().gt("totalAmount", 100)
+  .findList();
+```
+
+The dynamic `HAVING` clause is injected before the static trailing `ORDER BY`,
+even though `${having}` is the only placeholder present. Because there's no
+`${orderBy}`/`${andOrderBy}` placeholder here, a caller-supplied `.orderBy(...)`
+would be ignored - the ordering stays fixed as `order by order_id`.
+
+#### Example - both `${where}` and `${having}`
+
+```java
+String sql =
+  "select o.id as order_id, sum(d.qty * d.unit_price) as total_amount" +
+  " from o_order o join o_order_detail d on d.order_id = o.id" +
+  " ${where}" +
+  " group by o.id" +
+  " ${having}" +
+  " order by order_id";
+
+RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+  .columnMapping("order_id", "order.id")
+  .columnMapping("total_amount", "totalAmount")
+  .create();
+
+List<OrderAggregate> list = DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)
+  .where().gt("order.id", 0)
+  .having().gt("totalAmount", 50)
+  .findList();
+```
+
+Both the dynamic `WHERE` and dynamic `HAVING` are injected at their respective
+placeholders, and the trailing `order by order_id` is preserved after the
+`HAVING` clause.
+
+#### Example - `${orderBy}`, fully dynamic ordering
+
+Use `${orderBy}` when there's no static default ordering and you want the
+caller's `.orderBy(...)` to control it entirely:
+
+```java
+String sql =
+  "with order_totals as (" +
+  "  select o.id as order_id, sum(d.qty * d.unit_price) as total_amount" +
+  "  from o_order o join o_order_detail d on d.order_id = o.id" +
+  "  group by o.id" +
+  ")" +
+  " select order_id, total_amount from order_totals" +
+  " ${where}" +
+  " ${orderBy}";
+
+RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+  .columnMapping("order_id", "order.id")
+  .columnMapping("total_amount", "totalAmount")
+  .create();
+
+// executed SQL: ... where total_amount > ? order by total_amount desc
+List<OrderAggregate> list = DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)
+  .where().gt("totalAmount", 0)
+  .orderBy("totalAmount desc")
+  .findList();
+```
+
+If the caller doesn't call `.orderBy(...)`, nothing is injected at `${orderBy}`
+and no `ORDER BY` clause is emitted at all.
+
+#### Example - `${andOrderBy}`, appending to a static default ordering
+
+Use `${andOrderBy}` when there's a sensible static default ordering but you
+want callers to be able to add extra tie-breaker sort columns:
+
+```java
+String sql =
+  "... from order_totals" +
+  " ${where}" +
+  " order by total_amount desc ${andOrderBy}";
+
+RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+  .columnMapping("order_id", "order.id")
+  .columnMapping("total_amount", "totalAmount")
+  .create();
+
+// executed SQL: ... order by total_amount desc , order_id
+List<OrderAggregate> list = DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)
+  .where().gt("totalAmount", 0)
+  .orderBy("order.id")
+  .findList();
+```
+
+---
+
+## Using `fetchQuery()` to build out more of the graph
+
+A `RawSql` query can be the **root query** and still use `fetchQuery(path)` the
+same way an ordinary ORM query does - Ebean runs the raw SQL for the root rows,
+then runs additional secondary ORM queries to populate the requested paths. This
+lets you hand-write only the part of the query that needs raw SQL (e.g. an
+aggregate/CTE) and let the ORM build out the rest of the object graph normally.
+
+```java
+List<OrderAggregate> list = DB.find(OrderAggregate.class)
+  .setRawSql(rawSql)           // root query - runs the CTE/aggregate SQL
+  .fetchQuery("order")         // secondary query - loads the full Order
+  .fetchQuery("order.details") // secondary query - loads Order.details
+  .where().gt("totalAmount", 50)
+  .findList();
+```
+
+This executes **three** queries: the raw SQL root query, then one secondary
+query per `fetchQuery(path)` call.
+
+**Important**: if the raw SQL's column mapping only populates part of an
+association (e.g. only `order.id`, as in the examples above), that association
+is a *partial reference*. To load a nested to-many under it (e.g.
+`order.details`), you must add an explicit `fetchQuery(...)` (or `fetch(...)`)
+for the **intermediate path** (`order`) as well as the nested path
+(`order.details`) - `fetchQuery("order.details")` alone will leave `details` as
+a deferred/lazy collection, because Ebean doesn't otherwise have a fetch node
+for `order` to hang the secondary query off. If the raw SQL already selects the
+full set of columns for an association directly (no partial reference), this
+extra step isn't needed.
+
+This is the same `fetchQuery()` mechanism used for ordinary query bean queries -
+see [Use `fetchQuery()` for to-many paths](writing-ebean-query-beans.md#step-7---use-fetchquery-for-to-many-paths-and-fetchgroup-for-reusable-query-shapes)
+for background on why to-many paths are loaded via secondary queries rather than
+a single joined query.
+
+---
+
+## Column mapping
+
+Every `RawSqlBuilder` (except a bare `unparsed(sql)` with implicit positional
+mapping) uses `columnMapping(dbColumn, propertyName)` to map SQL result columns
+to bean properties:
+
+```java
+.columnMapping("order_id", "order.id")   // maps to the "order" association's "id" property
+.columnMapping("total_amount", "totalAmount")
+```
+
+- Dotted property paths (e.g. `"order.id"`) map a column into a nested/associated
+  bean property.
+- `columnMappingIgnore(dbColumn)` marks a selected column as intentionally unmapped
+  (present in the SQL but not needed on the bean).
+- `tableAliasMapping(tableAlias, path)` bulk-renames every mapping using a given
+  SQL table alias to be prefixed with a bean property path - handy when a `parse()`
+  query selects many columns from a joined table (e.g. alias `c` → path `customer`)
+  and you don't want to repeat the prefix in every `columnMapping()` call.
+
+---
+
+## Using `RawSql` with query beans
+
+`RawSql` is not limited to the plain `Query<T>` API - it also works with a
+generated query bean, giving type-safe `where()`/`having()`-equivalent
+expressions (as bean properties) over hand-written SQL. Every generated query
+bean exposes `setRawSql(...)`:
+
+```java
+RawSql rawSql = RawSqlBuilder.parse("select id, name, status from customer")
+  .columnMapping("id", "id")
+  .columnMapping("name", "name")
+  .columnMapping("status", "status")
+  .create();
+
+List<Customer> customers = new QCustomer()
+  .setRawSql(rawSql)
+  .status.equalTo(Customer.Status.ACTIVE) // typed expression, injected into the parsed WHERE clause
+  .findList();
+```
+
+This also works with `withPlaceholders(sql)` and an `@Sql` query bean:
+
+```java
+List<OrderAggregate> list = new QOrderAggregate()
+  .setRawSql(rawSql) // built with withPlaceholders() as shown above
+  .totalAmount.gt(100)
+  .findList();
+```
+
+The typed property expression (`.totalAmount.gt(100)`) is translated to a bound
+predicate and injected at the `${where}`/`${having}` placeholder position, exactly
+as `.where().gt("totalAmount", 100)` would be on the plain `Query<T>` API.
+
+---
+
+## Common anti-patterns
+
+### Anti-pattern 1 - reaching for raw SQL before trying a query bean
+
+Complex-looking joins are often just ordinary association traversal in a query
+bean. Don't use raw SQL just because a query touches several tables - see
+[Write Ebean queries with query beans](writing-ebean-query-beans.md).
+
+### Anti-pattern 2 - using `parse(sql)` on a CTE or window-function query
+
+`parse(sql)` will throw a parsing exception (or silently mis-locate the WHERE
+injection point) on SQL it can't understand structurally. If your SQL starts
+with `WITH ...` or has a subquery in `FROM`, use `withPlaceholders(sql)` instead.
+
+### Anti-pattern 3 - filtering on a same-level SELECT alias
+
+You cannot add a dynamic `WHERE` predicate on a `SELECT`-clause alias in the
+same query level (e.g. `select sum(x) as total ... ${where}` - `total` isn't a
+real column yet at the `WHERE` stage of that query level). Either:
+
+- move the aggregation into a CTE and filter on the CTE's output column in the
+  outer query (`WHERE` case), or
+- use `${having}`/`${andHaving}` to filter on the aggregate at the `HAVING` stage
+  of the same query level, where the aggregate expression is valid.
+
+### Anti-pattern 4 - forgetting `columnMapping()` with `unparsed()`/`withPlaceholders()`
+
+Both `unparsed(sql)` and `withPlaceholders(sql)` require **every** returned
+column to be explicitly mapped (or explicitly ignored via
+`columnMappingIgnore(...)`) - there's no column-list parsing to infer them.
+
+---
+
+## Troubleshooting
+
+| Symptom | Likely cause | Fix |
+|---------|--------------|-----|
+| `RuntimeException: Error parsing sql, can not find ... keyword` | `parse(sql)` used on SQL with a CTE, window function, or subquery in `FROM` | Use `RawSqlBuilder.withPlaceholders(sql)` instead |
+| `IllegalArgumentException: withPlaceholders() requires at least one of ${where}, ${andWhere}, ${having}, ${andHaving}, ${orderBy}, ${andOrderBy}...` | None of the six placeholder tokens were found in the SQL | Add the appropriate placeholder token at the injection point |
+| Dynamic `WHERE`/`HAVING` predicate silently has no effect, or query throws | Used `unparsed(sql)` and then tried to add a predicate | `unparsed(sql)` queries cannot be modified - switch to `parse(sql)` or `withPlaceholders(sql)` |
+| Generated SQL is invalid / clauses appear in the wrong order | Predicates added via `.where()`/`.having()` don't match the placeholders actually present in the SQL | Make sure `${where}`/`${having}` (or the `and` variants) exist at the point you expect predicates to be injected |
+| `.orderBy(...)`/`.order(...)` on the query silently has no effect | The SQL has no `${orderBy}`/`${andOrderBy}` placeholder | This is by design - without one of those placeholders there's no defined injection point, so the ordering is ignored rather than corrupting the SQL. Add `${orderBy}` or `${andOrderBy}` if you need caller-controlled ordering |
+| `Unknown column` / unmapped property error | Missing `columnMapping()` for a selected column | Add a `columnMapping(...)` or `columnMappingIgnore(...)` for every SQL column |
+| `fetchQuery("a.b")` collection stays deferred/lazy | `a` is a partial reference from the raw SQL column mapping (e.g. only `a.id` mapped), and there's no fetch node for `a` itself | Add `fetchQuery("a")` (or `fetch("a")`) alongside `fetchQuery("a.b")` |
+
+---
+
+## Related documentation
+
+- [Write Ebean queries with query beans](writing-ebean-query-beans.md)
+- [Derived / formula properties (`@Formula`, `@Formula2`)](derived-formula-properties.md)
+- [Ebean query docs](https://ebean.io/docs/query/)

docs/guides/writing-ebean-query-beans.md

@@ -462,6 +462,11 @@ List<CustomerSummary> summaries = new QCustomer()
 - the result is not going to be updated and saved back as an entity
 - the query contains formulas or aggregation intended for a read model
 
+`asDto(...)` maps a **flat**, single-row result. If the target DTO itself needs nested
+DTO fields (ToOne/ToMany) mirroring part of the entity graph, use
+`mapTo(Dto.class)` instead — see
+[Mapping entity graphs to DTOs](mapping-entity-graphs-to-dtos.md).
+
 ---
 
 ## Step 9 - Only fall back to raw SQL when the ORM query is not a good fit
@@ -483,6 +488,30 @@ Prefer the following order:
 Do **not** jump to raw SQL just because the query joins multiple tables. Query
 beans already handle ordinary relationship traversal well.
 
+### Using `RawSql` with query beans
+
+`RawSql` is not limited to the plain `Query<T>` API - it also works with a
+generated query bean, giving type-safe `where()`/`having()` expressions over
+hand-written SQL. Every generated query bean exposes `setRawSql(...)`:
+
+```java
+RawSql rawSql = RawSqlBuilder.parse("select id, name, status from customer")
+  .columnMapping("id", "id")
+  .columnMapping("name", "name")
+  .columnMapping("status", "status")
+  .create();
+
+List<Customer> customers = new QCustomer()
+  .setRawSql(rawSql)
+  .status.equalTo(Customer.Status.ACTIVE) // typed expression, injected into the parsed WHERE clause
+  .findList();
+```
+
+For the full guide to building `RawSql` - including `unparsed()`,
+`withPlaceholders()` for CTEs/window functions, the `${where}` / `${andWhere}`
+/ `${having}` / `${andHaving}` placeholder reference, and column mapping - see
+[Using `RawSql` with Ebean](using-rawsql-with-ebean.md).
+
 ---
 
 ## Common anti-patterns
@@ -570,4 +599,5 @@ When asked to add or modify an Ebean query:
 - [Add Ebean Postgres Maven POM](add-ebean-postgres-maven-pom.md)
 - [Entity Bean Creation](entity-bean-creation.md)
 - [Immutable bean cache for read-only references](immutable-bean-cache.md)
+- [Using `RawSql` with Ebean](using-rawsql-with-ebean.md)
 - [Ebean query docs](https://ebean.io/docs/query/)

ebean-api/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
 
   <name>ebean api</name>

ebean-api/src/main/java/io/ebean/DB.java

@@ -457,6 +457,10 @@ public final class DB {
 
   /**
    * Same as {@link #checkUniqueness(Object)} but with given transaction.
+   * <p>
+   * For control over query cache use and whether to skip the check when the bean's unique
+   * properties are unchanged, use {@link Database#checkUniqueness(Object, Transaction, boolean, boolean)}
+   * via {@link #getDefault()} instead.
    */
   public static Set<Property> checkUniqueness(Object bean, Transaction transaction) {
     return getDefault().checkUniqueness(bean, transaction);

ebean-api/src/main/java/io/ebean/Database.java

@@ -1078,12 +1078,21 @@ public interface Database {
    * @param bean The entity bean to check uniqueness on
    * @return a set of Properties if constraint validation was detected or empty list.
    */
-  Set<Property> checkUniqueness(Object bean);
+  default Set<Property> checkUniqueness(Object bean) {
+    return checkUniqueness(bean, null, false, true);
+  }
 
   /**
    * Same as {@link #checkUniqueness(Object)}. but with given transaction.
    */
-  Set<Property> checkUniqueness(Object bean, Transaction transaction);
+  default Set<Property> checkUniqueness(Object bean, Transaction transaction) {
+    return checkUniqueness(bean, transaction, false, true);
+  }
+
+  /**
+   * Same as {@link #checkUniqueness(Object)}. but with given transaction and extended search options.
+   */
+  Set<Property> checkUniqueness(Object bean, Transaction transaction, boolean useQueryCache, boolean skipClean);
 
   /**
    * Marks the entity bean as dirty.

ebean-api/src/main/java/io/ebean/DatabaseBuilder.java

@@ -62,9 +62,10 @@ public interface DatabaseBuilder {
   /**
    * Build and return the Database instance.
    * <p>
-   * When {@link #setRegister(boolean)} is set to true, and a database with the same
-   * name is already registered, this may return the existing registered database
-   * rather than creating a new one.
+   * When {@link #setRegister(boolean)} is set to true (the default), and a database
+   * with the same name is already registered, this throws an {@link IllegalStateException}.
+   * Use a unique name, or use {@link #setRegister(boolean)} with {@code false} if the
+   * Database instance is not intended to be registered/looked up by name.
    */
   Database build();
 
@@ -887,6 +888,13 @@ public interface DatabaseBuilder {
   @Deprecated
   DatabaseBuilder setBackgroundExecutorWrapper(BackgroundExecutorWrapper backgroundExecutorWrapper);
 
+  /**
+   * Enable tenant-partitioned caches. When enabled each tenant gets its own cache namespace,
+   * improving cache-hit ratio by preventing cross-tenant key collisions.
+   * Use {@link SpiCacheManager#clearTenant(Object)} when a tenant is deactivated.
+   */
+  DatabaseBuilder tenantPartitionedCache(boolean tenantPartitionedCache);
+
   /**
    * Set the L2 cache default max size.
    */
@@ -2567,6 +2575,11 @@ public interface DatabaseBuilder {
      */
     boolean isAutoPersistUpdates();
 
+    /**
+     * Return true if caches are partitioned by tenant.
+     */
+    boolean isTenantPartitionedCache();
+
     /**
      * Return the L2 cache default max size.
      */

ebean-api/src/main/java/io/ebean/DatabaseFactory.java

@@ -7,8 +7,6 @@ import jakarta.persistence.PersistenceException;
 
 import java.util.concurrent.locks.ReentrantLock;
 
-import static java.lang.System.Logger.Level.WARNING;
-
 /**
  * Low-level factory for creating {@link Database} instances.
  * <p>
@@ -81,10 +79,10 @@ public final class DatabaseFactory {
         // We're explicitly creating a database to be registered, so avoid
         // triggering DbContext static initialisation to auto-create a default one.
         DbPrimary.setSkip(true);
-        Database existing = DbContext.getInstance().getRegistered(name);
-        if (existing != null) {
-          EbeanVersion.log.log(WARNING, "Using existing database with name:{0}", name);
-          return existing;
+        if (DbContext.getInstance().contains(name)) {
+          throw new IllegalStateException("A Database with name [" + name + "] is already registered."
+            + " Use a unique DatabaseConfig name, or set DatabaseConfig.setRegister(false)"
+            + " if this Database instance is not intended to be registered/looked up by name.");
         }
       }
       Database server = createInternal(config);
@@ -123,6 +121,24 @@ public final class DatabaseFactory {
     }
   }
 
+  /**
+   * Remove the registration of this Database.
+   * <p>
+   * This is invoked when a Database is shutdown so that its registered name
+   * becomes available again for a subsequently created Database with the same name.
+   */
+  public static void unregister(Database server) {
+    lock.lock();
+    try {
+      DbContext.getInstance().deregister(server);
+      if (server.name().equals(defaultServerName)) {
+        defaultServerName = null;
+      }
+    } finally {
+      lock.unlock();
+    }
+  }
+
   /**
    * Shutdown gracefully all Database instances cleaning up any resources as required.
    * <p>

ebean-api/src/main/java/io/ebean/DbContext.java

@@ -4,7 +4,6 @@ import io.ebean.config.BeanNotEnhancedException;
 import io.ebean.datasource.DataSourceConfigurationException;
 
 import jakarta.persistence.PersistenceException;
-import org.jspecify.annotations.Nullable;
 
 import java.util.HashMap;
 import java.util.concurrent.ConcurrentHashMap;
@@ -77,9 +76,8 @@ final class DbContext {
     return defaultDatabase;
   }
 
-  @Nullable
-  Database getRegistered(String name) {
-    return concMap.get(name);
+  boolean contains(String name) {
+    return concMap.containsKey(name);
   }
 
   /**
@@ -122,6 +120,27 @@ final class DbContext {
     registerWithName(server.name(), server, isDefault);
   }
 
+  /**
+   * Remove the registration for this Database (typically on shutdown) so that
+   * its name becomes available again for a subsequently created Database.
+   * <p>
+   * Only removes the registration if it currently maps to this exact instance
+   * (avoids removing a different Database subsequently registered with the same name).
+   */
+  void deregister(Database server) {
+    lock.lock();
+    try {
+      String name = server.name();
+      concMap.remove(name, server);
+      syncMap.remove(name, server);
+      if (defaultDatabase == server) {
+        defaultDatabase = null;
+      }
+    } finally {
+      lock.unlock();
+    }
+  }
+
   private void registerWithName(String name, Database server, boolean isDefault) {
     lock.lock();
     try {

ebean-api/src/main/java/io/ebean/DtoConverterManager.java

@@ -0,0 +1,65 @@
+package io.ebean;
+
+import jakarta.persistence.PersistenceException;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Static bridge registering custom {@code @DtoConvert} converter instances so generated DTO
+ * mappers can reach them.
+ * <p>
+ * Generated mappers (see {@code query.mapTo(SomeDto.class)}) are wired via {@code ServiceLoader}
+ * as plain, no-arg-constructed, compile-time singletons (mirroring how entity/query-bean
+ * registration already works) - they have no way to reach a dependency-injection container, or
+ * any particular {@code Database} instance, at construction time. When a
+ * {@code @DtoConvert(value = ConverterType.class, method = "...")} property's converter is an
+ * <b>instance</b> method (as opposed to a {@code static} one, which is called directly with no
+ * registration needed at all), the generated mapper resolves it via {@link #get(Class)} - so the
+ * application must register an instance here, typically one already built by its own DI
+ * container, <b>before</b> building the {@code Database}:
+ * <pre>{@code
+ * AES256Cipher cipher = ...; // already DI-constructed
+ * DtoConverterManager.put(DriverConversions.class, new DriverConversionsImpl(cipher));
+ *
+ * Database db = DatabaseFactory.create(...); // generated mappers resolve converters from here
+ * }</pre>
+ * <p>
+ * This is a deliberate, narrowly-scoped exception to preferring dependency injection over static
+ * mutable state - it exists solely to bridge an already-DI-constructed singleton into
+ * {@code ServiceLoader}-discovered, no-arg-constructed generated code, which cannot otherwise
+ * reach a DI container or a specific {@code Database} instance. {@link #get(Class)} throws
+ * immediately if nothing was registered for the given type, so a missing/late registration fails
+ * fast at {@code Database} build time (a generated mapper's eager field initializer) rather than
+ * lazily on first use.
+ */
+public final class DtoConverterManager {
+
+  private static final Map<Class<?>, Object> converters = new ConcurrentHashMap<>();
+
+  private DtoConverterManager() {
+  }
+
+  /**
+   * Register a converter instance for the given type - must be called before the
+   * {@code Database} using it is built.
+   */
+  public static <T> void put(Class<T> type, T instance) {
+    converters.put(type, instance);
+  }
+
+  /**
+   * Return the registered converter instance for the given type.
+   *
+   * @throws PersistenceException if no instance was registered for {@code type}.
+   */
+  @SuppressWarnings("unchecked")
+  public static <T> T get(Class<T> type) {
+    T instance = (T) converters.get(type);
+    if (instance == null) {
+      throw new PersistenceException("No " + type.getName() + " registered - call "
+        + "DtoConverterManager.put(" + type.getSimpleName() + ".class, ...) before starting the Database");
+    }
+    return instance;
+  }
+}

ebean-api/src/main/java/io/ebean/DtoMapContext.java

@@ -0,0 +1,51 @@
+package io.ebean;
+
+import java.util.HashMap;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.function.Function;
+
+/**
+ * Identity-keyed cache of already-mapped source -> target instances, shared across one
+ * top-level {@link DtoMapper#mapList(java.util.List)} call (or an explicitly shared context).
+ * <p>
+ * Keyed by source object <b>identity</b> (an {@link IdentityHashMap}, not {@code equals()}/
+ * {@code hashCode()}) because the source is an Ebean entity graph, where repeated references to
+ * the same row within one query already resolve to the same Java object instance.
+ * <p>
+ * The identity map is partitioned <b>per target DTO type</b>. This matters because the same
+ * source instance can legitimately need to be mapped to more than one target type within a
+ * single graph - e.g. a top-level {@code CustomerDtoMapper} maps a {@code Customer} to a full
+ * {@code CustomerDto}, while a nested {@code ContactDtoMapper} maps the very same {@code Customer}
+ * instance (accessed via {@code contact.getCustomer()}) to a shallow {@code CustomerRefDto} to
+ * avoid a cycle. A single un-partitioned {@code IdentityHashMap<Object,Object>} would have the
+ * two mappers collide on the same source key and incorrectly hand back the other mapper's
+ * (wrong-typed) cached result. Partitioning by target type keeps each mapper's cache isolated
+ * while still sharing one context/instance per top-level mapping call.
+ * <p>
+ * Not thread-safe - a context is expected to be created per top-level mapping call and not
+ * shared across threads.
+ */
+public final class DtoMapContext {
+
+  private final Map<Class<?>, Map<Object, Object>> mappedByType = new HashMap<>();
+
+  /**
+   * Return the already-mapped target for the given source instance if present, otherwise map it
+   * via {@code mappingFunction}, register it, and return it.
+   *
+   * @param targetType the DTO type being produced - used to partition the identity cache so that
+   *     mapping the same source to different target types never collides.
+   */
+  @SuppressWarnings("unchecked")
+  public <S, T> T computeIfAbsent(Class<T> targetType, S source, Function<S, T> mappingFunction) {
+    Map<Object, Object> mapped = mappedByType.computeIfAbsent(targetType, t -> new IdentityHashMap<>());
+    T existing = (T) mapped.get(source);
+    if (existing != null) {
+      return existing;
+    }
+    T created = mappingFunction.apply(source);
+    mapped.put(source, created);
+    return created;
+  }
+}

ebean-api/src/main/java/io/ebean/DtoMapper.java

@@ -0,0 +1,76 @@
+package io.ebean;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Mapper interface implemented by generated (or hand-written) entity -> DTO graph mappers.
+ * <p>
+ * Used with nested entity-to-DTO graph mapping (see {@code query.mapTo(SomeDto.class)}) as
+ * distinct from the existing flat, single-row {@link DtoQuery} pipeline. Each entity/DTO type
+ * pair gets its own small, composable mapper implementation (mirroring MapStruct's per-type
+ * mapper generation) rather than one large mapper inlining every nested type. Nested mappers are
+ * wired together via constructor injection, not static singletons - this keeps mappers stateless,
+ * substitutable (e.g. for tests) and avoids global mutable state.
+ * <p>
+ * A {@link DtoMapContext} is threaded through every nested {@code map(...)} call within one
+ * top-level {@link #mapList(List)} invocation, so that repeated references to the same source
+ * entity instance (e.g. several {@code Contact}s sharing the same {@code Customer}) map to the
+ * <b>same</b> target DTO instance rather than creating duplicate-but-equal copies. This mirrors
+ * the identity semantics Ebean's own entity graph already has, and is what makes the resulting
+ * DTO graph "graph shaped" rather than "tree of copies shaped".
+ * <p>
+ * Implementations contain no reflection or {@code MethodHandles} - only direct getter calls and
+ * constructor invocation - so generated mappers are safe under GraalVM native-image with zero
+ * additional reachability metadata.
+ *
+ * @param <SOURCE> the source entity (or embeddable) type
+ * @param <TARGET> the target DTO type
+ */
+public interface DtoMapper<SOURCE, TARGET> {
+
+  /**
+   * Return the {@link FetchGroup} of exactly the source properties (and nested paths) needed to
+   * populate the target DTO graph - the select()/fetch() spec is derived from the DTO's declared
+   * shape rather than maintained separately by hand. Used by {@code query.mapTo(TARGET.class)}
+   * to automatically apply the correct fetch spec before the query is executed.
+   */
+  FetchGroup<SOURCE> fetchGroup();
+
+  /**
+   * Map a single source instance to its target DTO, reusing/registering the mapping in the
+   * given context so that repeated references to the same source instance de-duplicate to the
+   * same target instance. Must return {@code null} when given {@code null}.
+   */
+  TARGET map(SOURCE source, DtoMapContext context);
+
+  /**
+   * Map a single source instance using a fresh, one-off context. Convenience for mapping a
+   * single object in isolation (no de-duplication opportunity since there's nothing else in
+   * scope to de-duplicate against).
+   */
+  default TARGET map(SOURCE source) {
+    return map(source, new DtoMapContext());
+  }
+
+  /**
+   * Map a list of source instances to a list of target DTOs sharing the given context,
+   * preserving order.
+   */
+  default List<TARGET> mapList(List<SOURCE> source, DtoMapContext context) {
+    List<TARGET> result = new ArrayList<>(source.size());
+    for (SOURCE s : source) {
+      result.add(map(s, context));
+    }
+    return result;
+  }
+
+  /**
+   * Map a list of source instances to a list of target DTOs using a fresh context shared across
+   * the whole list - this is the usual top-level entry point, e.g. mapping the result of a
+   * {@code query.findList()} call.
+   */
+  default List<TARGET> mapList(List<SOURCE> source) {
+    return mapList(source, new DtoMapContext());
+  }
+}

ebean-api/src/main/java/io/ebean/DtoMapperManager.java

@@ -0,0 +1,125 @@
+package io.ebean;
+
+import io.ebean.config.DtoMapperRegister;
+import jakarta.persistence.PersistenceException;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.ServiceLoader;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Loads all generated {@link DtoMapperRegister} implementations (via {@code ServiceLoader},
+ * mirroring how {@code EntityClassRegister} is discovered) once, and resolves the {@link
+ * DtoMapper} for a given (source, dto) pair, or by the generated mapper's own concrete type, on
+ * request.
+ * <p>
+ * Has no dependency on {@link Database} - it can be constructed independently, before (or
+ * without) a {@code Database} existing at all, e.g. as a DI-managed singleton constructed
+ * alongside the rest of an application's dependency graph. If you want the exact same instance
+ * (and hence the exact same underlying mapper instances) shared between {@code query.mapTo(...)}
+ * and your own application code, construct it yourself and register it via {@code
+ * DatabaseBuilder.putServiceObject(DtoMapperManager.class, myManager)} before building the {@code
+ * Database} - it is then used instead of a Database-internal default instance.
+ * <p>
+ * Resolved mappers are cached so that repeated lookups only ever pay the cost of iterating the
+ * generated registers and constructing the mapper (and its nested mapper/{@code FetchGroup}
+ * graph) once - after that, every lookup is a single hash-map hit regardless of how many entity/
+ * DTO pairs are registered.
+ */
+public final class DtoMapperManager {
+
+  private final List<DtoMapperRegister> registers;
+  private final ConcurrentHashMap<MapperKey, DtoMapper<?, ?>> pairCache = new ConcurrentHashMap<>();
+  private final ConcurrentHashMap<Class<?>, Object> typeCache = new ConcurrentHashMap<>();
+
+  public DtoMapperManager() {
+    this.registers = load();
+  }
+
+  private static List<DtoMapperRegister> load() {
+    List<DtoMapperRegister> result = new ArrayList<>();
+    for (DtoMapperRegister register : ServiceLoader.load(DtoMapperRegister.class)) {
+      result.add(register);
+    }
+    return result;
+  }
+
+  /**
+   * Return the {@link DtoMapper} for the given (source, dto) pair.
+   *
+   * @throws PersistenceException if no generated mapper is registered for that pair.
+   */
+  @SuppressWarnings("unchecked")
+  public <S, D> DtoMapper<S, D> mapperFor(Class<S> sourceType, Class<D> dtoType) {
+    return (DtoMapper<S, D>) pairCache.computeIfAbsent(new MapperKey(sourceType, dtoType), this::resolve);
+  }
+
+  /**
+   * Return the generated mapper instance of the given concrete mapper type - e.g. {@code
+   * manager.get(CustomerDtoMapper.class)} - typically used to resolve a mapper instance for
+   * dependency injection into application code (e.g. an avaje-inject {@code @Factory} bean
+   * method).
+   *
+   * @throws PersistenceException if no generated mapper of that type is registered.
+   */
+  @SuppressWarnings("unchecked")
+  public <T> T get(Class<T> mapperType) {
+    return (T) typeCache.computeIfAbsent(mapperType, this::resolveByType);
+  }
+
+  private DtoMapper<?, ?> resolve(MapperKey key) {
+    for (DtoMapperRegister register : registers) {
+      DtoMapper<?, ?> mapper = register.mapperFor(key.sourceType, key.dtoType);
+      if (mapper != null) {
+        return mapper;
+      }
+    }
+    throw new PersistenceException("No DtoMapper registered mapping " + key.sourceType + " -> " + key.dtoType
+      + " - check @DtoMapping(source = " + key.sourceType.getSimpleName() + ".class, target = "
+      + key.dtoType.getSimpleName() + ".class) is declared on a package-info.java processed by querybean-generator");
+  }
+
+  private Object resolveByType(Class<?> mapperType) {
+    for (DtoMapperRegister register : registers) {
+      Object mapper = register.mapperOfType(mapperType);
+      if (mapper != null) {
+        return mapper;
+      }
+    }
+    throw new PersistenceException("No DtoMapper of type " + mapperType.getName() + " registered"
+      + " - check a @DtoMapping(...) pair generating " + mapperType.getSimpleName()
+      + " is declared on a package-info.java processed by querybean-generator");
+  }
+
+  /**
+   * Cache key pairing the source entity type and target DTO type.
+   */
+  private static final class MapperKey {
+
+    private final Class<?> sourceType;
+    private final Class<?> dtoType;
+
+    MapperKey(Class<?> sourceType, Class<?> dtoType) {
+      this.sourceType = sourceType;
+      this.dtoType = dtoType;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (!(o instanceof MapperKey)) {
+        return false;
+      }
+      MapperKey other = (MapperKey) o;
+      return sourceType == other.sourceType && dtoType == other.dtoType;
+    }
+
+    @Override
+    public int hashCode() {
+      return 31 * sourceType.hashCode() + dtoType.hashCode();
+    }
+  }
+}

ebean-api/src/main/java/io/ebean/DtoMapperSupport.java

@@ -0,0 +1,137 @@
+package io.ebean;
+
+/**
+ * Runtime helpers used by generated {@link DtoMapper} implementations to safely resolve a
+ * primitive-typed DTO field whose value is derived from a multi-hop {@code @DtoPath} that
+ * traverses a nullable intermediate relation.
+ * <p>
+ * A {@code null}-guarded getter-chain (e.g. {@code source.getOrganisation() == null ? null :
+ * source.getOrganisation().getId()}) always types as the boxed wrapper (since one branch is the
+ * {@code null} literal). When the DTO's target field is a primitive (e.g. {@code long
+ * organisationId}), passing that boxed expression to the constructor auto-unboxes it - which
+ * throws a raw, unhelpful {@link NullPointerException} if the relation really is {@code null}.
+ * <p>
+ * These methods give the generated mapper a choice, controlled by {@code @DtoPath#failOnNull()}:
+ * default to the primitive's zero-equivalent value ({@code orZero} methods, the default), or
+ * throw a clear, descriptive exception naming the offending property path ({@code require}
+ * methods, opted into via {@code failOnNull = true}).
+ *
+ * @see io.ebean.annotation.DtoPath
+ */
+public final class DtoMapperSupport {
+
+  private DtoMapperSupport() {
+  }
+
+  /** Return {@code 0} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static long orZero(Long value) {
+    return value == null ? 0L : value;
+  }
+
+  /** Return {@code 0} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static int orZero(Integer value) {
+    return value == null ? 0 : value;
+  }
+
+  /** Return {@code 0} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static short orZero(Short value) {
+    return value == null ? 0 : value;
+  }
+
+  /** Return {@code 0} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static byte orZero(Byte value) {
+    return value == null ? 0 : value;
+  }
+
+  /** Return {@code 0.0} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static double orZero(Double value) {
+    return value == null ? 0.0 : value;
+  }
+
+  /** Return {@code 0.0f} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static float orZero(Float value) {
+    return value == null ? 0.0f : value;
+  }
+
+  /** Return {@code false} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static boolean orZero(Boolean value) {
+    return value != null && value;
+  }
+
+  /** Return {@code '\u0000'} if {@code value} is {@code null}, otherwise its unboxed value. */
+  public static char orZero(Character value) {
+    return value == null ? '\u0000' : value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static long require(Long value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static int require(Integer value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static short require(Short value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static byte require(Byte value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static double require(Double value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static float require(Float value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static boolean require(Boolean value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  /** Return the unboxed value, or throw if {@code value} is {@code null}. */
+  public static char require(Character value, String path) {
+    if (value == null) {
+      throw failure(path);
+    }
+    return value;
+  }
+
+  private static IllegalStateException failure(String path) {
+    return new IllegalStateException(
+      "@DtoPath(\"" + path + "\") resolved to null via a nullable intermediate relation, but the"
+        + " target DTO field is primitive and failOnNull=true - either handle the null case in"
+        + " source data, use a boxed wrapper type for the DTO field, or remove failOnNull to"
+        + " default to the primitive's zero-equivalent value instead.");
+  }
+}

ebean-api/src/main/java/io/ebean/DtoQuery.java

@@ -1,16 +1,9 @@
 package io.ebean;
 
 import org.jspecify.annotations.NullMarked;
-import org.jspecify.annotations.Nullable;
 
-import javax.sql.DataSource;
-import java.sql.Connection;
 import java.util.Collection;
 import java.util.List;
-import java.util.Optional;
-import java.util.function.Consumer;
-import java.util.function.Predicate;
-import java.util.stream.Stream;
 
 /**
  * Query for performing native SQL queries that return DTO Bean's.
@@ -43,12 +36,7 @@ import java.util.stream.Stream;
  * }</pre>
  */
 @NullMarked
-public interface DtoQuery<T> extends CancelableQuery {
-
-  /**
-   * Execute the query returning a list.
-   */
-  List<T> findList();
+public interface DtoQuery<T> extends StreamableQuery<DtoQuery<T>, T> {
 
   /**
    * Execute the query iterating a row at a time.
@@ -59,56 +47,6 @@ public interface DtoQuery<T> extends CancelableQuery {
    */
   QueryIterator<T> findIterate();
 
-  /**
-   * Execute the query returning a Stream.
-   * <p>
-   * Note that the Stream holds resources related to the underlying
-   * resultSet and potentially connection and MUST be closed. We should use
-   * the Stream in a <em>try with resource block</em>.
-   */
-  Stream<T> findStream();
-
-  /**
-   * Execute the query iterating a row at a time.
-   * <p>
-   * This streaming type query is useful for large query execution as only 1 row needs to be held in memory.
-   * </p>
-   */
-  void findEach(Consumer<T> consumer);
-
-  /**
-   * Execute the query iterating the results and batching them for the consumer.
-   * <p>
-   * This runs like findEach streaming results from the database but just collects the results
-   * into batches to pass to the consumer.
-   *
-   * @param batch    The number of dto beans to collect before given them to the consumer
-   * @param consumer The consumer to process the batch of DTO beans
-   */
-  void findEach(int batch, Consumer<List<T>> consumer);
-
-  /**
-   * Execute the query iterating a row at a time with the ability to stop consuming part way through.
-   * <p>
-   * Returning false after processing a row stops the iteration through the query results.
-   * </p>
-   * <p>
-   * This streaming type query is useful for large query execution as only 1 row needs to be held in memory.
-   * </p>
-   */
-  void findEachWhile(Predicate<T> consumer);
-
-  /**
-   * Execute the query returning a single bean.
-   */
-  @Nullable
-  T findOne();
-
-  /**
-   * Execute the query returning an optional bean.
-   */
-  Optional<T> findOneOrEmpty();
-
   /**
    * Bind all the parameters using index positions.
    * <p>
@@ -215,35 +153,41 @@ public interface DtoQuery<T> extends CancelableQuery {
   DtoQuery<T> setBufferFetchSizeHint(int bufferFetchSizeHint);
 
   /**
-   * Use the explicit transaction to execute the query.
-   */
-  DtoQuery<T> usingTransaction(Transaction transaction);
-
-  /**
-   * Execute the query using the given connection.
-   */
-  DtoQuery<T> usingConnection(Connection connection);
-
-  /**
-   * Ensure that the master DataSource is used if there is a read only data source
-   * being used (that is using a read replica database potentially with replication lag).
+   * Return a PagedList for this query using firstRow and maxRows.
    * <p>
-   * When the database is configured with a read-only DataSource via
-   * say {@link io.ebean.DatabaseBuilder#readOnlyDataSource(DataSource)} then
-   * by default when a query is run without an active transaction, it uses the read-only data
-   * source. We use {@code usingMaster()} to instead ensure that the query is executed
-   * against the master data source.
-   */
-  default DtoQuery<T> usingMaster() {
-    return usingMaster(true);
-  }
-
-  /**
-   * Ensure the master DataSource is used when useMaster is true. Otherwise, the read only
-   * data source can be used if defined.
+   * The benefit of using this over findList() is that it provides functionality to get the
+   * total row count etc.
+   * <p>
+   * If maxRows is not set on the query prior to calling findPagedList() then a
+   * PersistenceException is thrown.
+   * <p>
+   * This is only supported for a DtoQuery that is derived from an ORM query via
+   * {@link Query#asDto(Class)} / {@link ExpressionList#asDto(Class)}. It is not supported
+   * for a DtoQuery based on raw SQL (e.g. via {@link Database#findDto(Class, String)}) as
+   * there is no query structure available from which to derive a matching row count query -
+   * a PersistenceException is thrown in that case.
+   * <pre>{@code
    *
-   * @see #usingMaster()
+   *  PagedList<OrderDto> pagedList =
+   *    DB.find(Order.class)
+   *       .where().eq("status", Order.Status.NEW)
+   *       .orderBy().asc("id")
+   *       .setFirstRow(50)
+   *       .setMaxRows(20)
+   *       .asDto(OrderDto.class)
+   *       .findPagedList();
+   *
+   *       // fetch the total row count in the background
+   *       pagedList.loadCount();
+   *
+   *       List<OrderDto> orders = pagedList.getList();
+   *       int totalRowCount = pagedList.getTotalCount();
+   *
+   * }</pre>
+   *
+   * @return The PagedList
    */
-  DtoQuery<T> usingMaster(boolean useMaster);
+  @Override
+  PagedList<T> findPagedList();
 
 }

ebean-api/src/main/java/io/ebean/ExpressionList.java

@@ -10,6 +10,7 @@ import java.sql.Timestamp;
 import java.util.*;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
+import java.util.function.Supplier;
 
 /**
  * List of Expressions that make up a where or having clause.
@@ -103,6 +104,29 @@ public interface ExpressionList<T> {
    */
   <D> DtoQuery<D> asDto(Class<D> dtoClass);
 
+  /**
+   * Map the query result to a nested DTO graph, automatically deriving the select()/fetch() spec
+   * from the target DTO's declared shape and forcing {@code setUnmodifiable(true)}.
+   * <p>
+   * Distinct from {@link #asDto(Class)} (the flat, single-row SQL pipeline) - this supports
+   * nested ToOne/ToMany DTO graphs, mapped from the normal ORM entity query result.
+   *
+   * @throws jakarta.persistence.PersistenceException if no generated {@link DtoMapper} is
+   *     registered for this (entity, dto) pair.
+   */
+  <D> MappedQuery<D> mapTo(Class<D> dtoType);
+
+  /**
+   * Map the query result to a nested DTO graph using an already-resolved {@link DtoMapper}
+   * instance, rather than looking one up by (entity, dtoType) - e.g. to select a named variant
+   * mapper (see {@code @DtoMapping(name = "...", exclude = "...")}), such as
+   * {@code query.mapTo(User.class, userMapper.noFleets())}.
+   *
+   * @param dtoType the DTO type mapped to (must match {@code mapper}'s target type)
+   * @param mapper the mapper instance to use, e.g. a named variant accessor on a generated mapper
+   */
+  <D> MappedQuery<D> mapTo(Class<D> dtoType, DtoMapper<T, D> mapper);
+
   /**
    * Return the underlying query as an UpdateQuery.
    * <p>
@@ -205,6 +229,22 @@ public interface ExpressionList<T> {
    */
   int delete();
 
+  /**
+   * Execute as a delete query permanently deleting the 'root level' beans that match the
+   * predicates in the query without soft delete.
+   * <p>
+   * This is the same as {@link #delete()} except that when the bean type uses soft delete
+   * (e.g. {@code @SoftDelete}) the matching rows are permanently (hard) deleted rather than
+   * being marked as deleted.
+   * <p>
+   * Note that if the query includes joins then the generated delete statement may not be
+   * optimal depending on the database platform.
+   * </p>
+   *
+   * @return the number of rows that were permanently deleted.
+   */
+  int deletePermanent();
+
   /**
    * Execute as a update query.
    *
@@ -382,6 +422,26 @@ public interface ExpressionList<T> {
    */
   Optional<T> findOneOrEmpty();
 
+  /**
+   * Execute the query returning a single bean or throwing a {@link jakarta.persistence.EntityNotFoundException}
+   * if there is no matching bean.
+   *
+   * @see Query#findOneOrThrow()
+   */
+  default T findOneOrThrow() {
+    return query().findOneOrThrow();
+  }
+
+  /**
+   * Execute the query returning a single bean or throwing the exception produced by the
+   * given supplier if there is no matching bean.
+   *
+   * @see Query#findOneOrThrow(Supplier)
+   */
+  default T findOneOrThrow(Supplier<? extends RuntimeException> exceptionSupplier) {
+    return query().findOneOrThrow(exceptionSupplier);
+  }
+
   /**
    * Execute find row count query in a background thread.
    * <p>

ebean-api/src/main/java/io/ebean/FindableQuery.java

@@ -0,0 +1,89 @@
+package io.ebean;
+
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+import jakarta.persistence.EntityNotFoundException;
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Supplier;
+
+/**
+ * Common find operations shared by the query types that can execute and return
+ * results - {@link SqlQuery}, {@link DtoQuery}, {@link MappedQuery} and {@link QueryBuilder}.
+ *
+ * @param <SELF> The query type (used for method chaining)
+ * @param <T>    The type of the result
+ */
+@NullMarked
+public interface FindableQuery<SELF extends FindableQuery<SELF, T>, T> extends CancelableQuery {
+
+  /**
+   * Execute the query returning the list of results.
+   */
+  List<T> findList();
+
+  /**
+   * Execute the query returning a single result, or {@code null} if there is no matching row.
+   * <p>
+   * If more than 1 row is found for this query then a PersistenceException is thrown.
+   */
+  @Nullable
+  T findOne();
+
+  /**
+   * Execute the query returning an optional result.
+   */
+  Optional<T> findOneOrEmpty();
+
+  /**
+   * Execute the query returning a single result or throwing a
+   * {@link jakarta.persistence.EntityNotFoundException} if there is no matching row.
+   */
+  default T findOneOrThrow() {
+    return findOneOrEmpty().orElseThrow(() -> new EntityNotFoundException("Not found"));
+  }
+
+  /**
+   * Execute the query returning a single result or throwing the exception produced
+   * by the given supplier if there is no matching row.
+   */
+  default T findOneOrThrow(Supplier<? extends RuntimeException> exceptionSupplier) {
+    return findOneOrEmpty().orElseThrow(exceptionSupplier);
+  }
+
+  /**
+   * Execute the query using the given transaction.
+   */
+  SELF usingTransaction(Transaction transaction);
+
+  /**
+   * Execute the query using the given connection.
+   */
+  SELF usingConnection(Connection connection);
+
+  /**
+   * Ensure that the master DataSource is used if there is a read only data source
+   * being used (that is using a read replica database potentially with replication lag).
+   * <p>
+   * When the database is configured with a read-only DataSource via
+   * say {@link DatabaseBuilder#readOnlyDataSource(DataSource)} then
+   * by default when a query is run without an active transaction, it uses the read-only data
+   * source. We use {@code usingMaster()} to instead ensure that the query is executed
+   * against the master data source.
+   */
+  default SELF usingMaster() {
+    return usingMaster(true);
+  }
+
+  /**
+   * Ensure the master DataSource is used when useMaster is true. Otherwise, the read only
+   * data source can be used if defined.
+   *
+   * @see #usingMaster()
+   */
+  SELF usingMaster(boolean useMaster);
+
+}

ebean-api/src/main/java/io/ebean/MappedQuery.java

@@ -0,0 +1,111 @@
+package io.ebean;
+
+import org.jspecify.annotations.NullMarked;
+
+import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+
+/**
+ * Query that maps an entity graph query result to a nested DTO graph, produced by
+ * {@code query.mapTo(SomeDto.class)}.
+ * <p>
+ * Distinct from the existing flat, single-row {@link DtoQuery} pipeline (see {@link
+ * QueryBuilder#asDto(Class)}) - this executes the underlying entity ORM query (with the
+ * select()/fetch() spec automatically derived from the target DTO's declared shape, see
+ * {@link DtoMapper#fetchGroup()}), forces {@code setUnmodifiable(true)}, and then maps the
+ * resulting (unmodifiable) entity graph into a DTO graph via the generated {@link DtoMapper},
+ * supporting nested ToOne/ToMany and identity-aware de-duplication.
+ *
+ * @param <D> the target DTO type
+ */
+@NullMarked
+public interface MappedQuery<D> extends StreamableQuery<MappedQuery<D>, D> {
+
+  /**
+   * Execute the query returning the mapped DTO list.
+   */
+  @Override
+  List<D> findList();
+
+  /**
+   * Execute the query returning a paged list of mapped DTOs.
+   * <p>
+   * Mirrors {@code Query#findPagedList()} - the underlying entity graph query is paged (via
+   * {@code setFirstRow(int)}/{@code setMaxRows(int)}) and executed as normal, then each page's
+   * result is mapped to the target DTO graph. Row-count/page-index metadata
+   * ({@link PagedList#getTotalCount()}, {@link PagedList#hasNext()}, etc.) reflects the
+   * underlying entity query and is unaffected by the DTO mapping.
+   */
+  @Override
+  PagedList<D> findPagedList();
+
+  /**
+   * Execute the query returning the result as a Stream of mapped DTOs.
+   * <p>
+   * Mirrors {@link QueryBuilder#findStream()} - the underlying entity graph query is streamed
+   * (supporting very large queries iterating any number of results, potentially using multiple
+   * persistence contexts internally) and each entity is mapped to its target DTO lazily as the
+   * stream is consumed, sharing one {@link DtoMapContext} across the whole stream so that
+   * repeated references to the same source entity still de-duplicate to the same DTO instance.
+   * <pre>{@code
+   *
+   *  // use try with resources to ensure Stream is closed
+   *
+   *  try (Stream<CustomerDto> stream = query.mapTo(CustomerDto.class).findStream()) {
+   *    stream
+   *    .map(...)
+   *    .collect(...);
+   *  }
+   *
+   * }</pre>
+   */
+  @Override
+  Stream<D> findStream();
+
+  /**
+   * Execute the query processing the mapped DTOs one at a time.
+   * <p>
+   * Mirrors {@link QueryBuilder#findEach(Consumer)} - the underlying entity graph query is
+   * streamed one entity at a time and each entity is mapped to its target DTO lazily as it is
+   * consumed, sharing one {@link DtoMapContext} across the whole callback so that repeated
+   * references to the same source entity still de-duplicate to the same DTO instance.
+   * <p>
+   * This method is appropriate to process very large query results as the mapped DTOs are
+   * consumed one at a time and do not need to be held in memory (unlike {@link #findList()}).
+   *
+   * @param consumer the consumer used to process the mapped DTOs.
+   */
+  @Override
+  void findEach(Consumer<D> consumer);
+  /**
+   * Execute findEach streaming query batching the mapped DTOs for consuming.
+   * <p>
+   * Mirrors {@link QueryBuilder#findEach(int, Consumer)} - typically used when we want to do
+   * further processing on the mapped DTOs in batch form, for example 100 at a time. Each batch
+   * shares one {@link DtoMapContext} with the rest of the query so that repeated references to
+   * the same source entity still de-duplicate to the same DTO instance.
+   *
+   * @param batch    The number of mapped DTOs processed in the batch
+   * @param consumer Process the batch of mapped DTOs
+   */
+  @Override
+  void findEach(int batch, Consumer<List<D>> consumer);
+
+  /**
+   * Execute the query using callbacks to process the resulting mapped DTOs one at a time,
+   * with the ability to stop processing part way through.
+   * <p>
+   * Mirrors {@link QueryBuilder#findEachWhile(Predicate)} - returning {@code false} after
+   * processing a DTO stops the iteration through the query results. Sharing one
+   * {@link DtoMapContext} across the whole callback so that repeated references to the same
+   * source entity still de-duplicate to the same DTO instance.
+   *
+   * @param consumer the consumer used to process the mapped DTOs, returning {@code false} to
+   *                 stop processing.
+   */
+  @Override
+  void findEachWhile(Predicate<D> consumer);
+
+}

ebean-api/src/main/java/io/ebean/Query.java

@@ -151,7 +151,7 @@ import org.jspecify.annotations.Nullable;
  * @param <T> the type of Entity bean this query will fetch.
  */
 @NullMarked
-public interface Query<T> extends CancelableQuery, QueryBuilder<Query<T>, T> {
+public interface Query<T> extends QueryBuilder<Query<T>, T> {
 
   /**
    * The lock type (strength) to use with query FOR UPDATE row locking.

ebean-api/src/main/java/io/ebean/QueryBuilder.java

@@ -2,8 +2,7 @@ package io.ebean;
 
 import org.jspecify.annotations.Nullable;
 
-import javax.sql.DataSource;
-import java.sql.Connection;
+import jakarta.persistence.EntityNotFoundException;
 import java.sql.Timestamp;
 import java.util.List;
 import java.util.Map;
@@ -11,8 +10,6 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.function.BooleanSupplier;
 import java.util.function.Consumer;
-import java.util.function.Predicate;
-import java.util.stream.Stream;
 
 /**
  * Build and execute an ORM query.
@@ -20,7 +17,7 @@ import java.util.stream.Stream;
  * @param <SELF> The type of the builder
  * @param <T>    The entity bean type
  */
-public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends QueryBuilderProjection<SELF, T> {
+public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends QueryBuilderProjection<SELF, T>, StreamableQuery<SELF, T> {
 
   /**
    * Set root table alias.
@@ -77,6 +74,32 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
    */
   <D> DtoQuery<D> asDto(Class<D> dtoClass);
 
+  /**
+   * Map the query result to a nested DTO graph, automatically deriving the select()/fetch() spec
+   * from the target DTO's declared shape and forcing {@code setUnmodifiable(true)}.
+   * <p>
+   * Distinct from {@link #asDto(Class)} (the flat, single-row SQL pipeline) - this supports
+   * nested ToOne/ToMany DTO graphs, mapped from the normal ORM entity query result.
+   *
+   * @throws jakarta.persistence.PersistenceException if no generated {@link DtoMapper} is
+   *     registered for this (entity, dto) pair.
+   */
+  <D> MappedQuery<D> mapTo(Class<D> dtoType);
+
+  /**
+   * Map the query result to a nested DTO graph using an already-resolved {@link DtoMapper}
+   * instance, rather than looking one up by (entity, dtoType). Bypasses {@link DtoMapperManager}
+   * entirely, so it's the way to select a named variant mapper (see {@code @DtoMapping(name =
+   * "...", exclude = "...")}) - e.g. {@code query.mapTo(User.class, userMapper.noFleets())}.
+   * <p>
+   * Also forces {@code setUnmodifiable(true)} and derives the select()/fetch() spec from
+   * {@code mapper.fetchGroup()}, same as {@link #mapTo(Class)}.
+   *
+   * @param dtoType the DTO type mapped to (must match {@code mapper}'s target type)
+   * @param mapper the mapper instance to use, e.g. a named variant accessor on a generated mapper
+   */
+  <D> MappedQuery<D> mapTo(Class<D> dtoType, DtoMapper<T, D> mapper);
+
   /**
    * Convert the query to a UpdateQuery.
    * <p>
@@ -120,48 +143,16 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
    */
   SELF copy();
 
-  /**
-   * Execute the query using the given transaction.
-   */
-  SELF usingTransaction(Transaction transaction);
-
   /**
    * Execute this query using immutable bean cache values for matching bean types.
    */
   SELF using(ImmutableBeanCache<?> beanCache);
 
-  /**
-   * Execute the query using the given connection.
-   */
-  SELF usingConnection(Connection connection);
-
   /**
    * Execute the query using the given database.
    */
   SELF usingDatabase(Database database);
 
-  /**
-   * Ensure that the master DataSource is used if there is a read only data source
-   * being used (that is using a read replica database potentially with replication lag).
-   * <p>
-   * When the database is configured with a read-only DataSource via
-   * say {@link io.ebean.config.DatabaseConfig#setReadOnlyDataSource(DataSource)} then
-   * by default when a query is run without an active transaction, it uses the read-only data
-   * source. We we use {@code usingMaster()} to instead ensure that the query is executed
-   * against the master data source.
-   */
-  default SELF usingMaster() {
-    return usingMaster(true);
-  }
-
-  /**
-   * Ensure the master DataSource is used when useMaster is true. Otherwise, the read only
-   * data source can be used if defined.
-   *
-   * @see #usingMaster()
-   */
-  SELF usingMaster(boolean useMaster);
-
   /**
    * Set the base table to use for this query.
    * <p>
@@ -607,6 +598,21 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
    */
   int delete();
 
+  /**
+   * Execute as a delete query permanently deleting the 'root level' beans that match the
+   * predicates in the query without soft delete.
+   * <p>
+   * This is the same as {@link #delete()} except that when the bean type uses soft delete
+   * (e.g. {@code @SoftDelete}) the matching rows are permanently (hard) deleted rather than
+   * being marked as deleted.
+   * <p>
+   * Note that if the query includes joins then the generated delete statement may not be
+   * optimal depending on the database platform.
+   *
+   * @return the number of beans/rows that were permanently deleted.
+   */
+  int deletePermanent();
+
   /**
    * Execute the query returning true if a row is found.
    * <p>
@@ -638,88 +644,24 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
   boolean exists();
 
   /**
-   * Execute the query returning either a single bean or null (if no matching
-   * bean is found).
-   * <p>
-   * If more than 1 row is found for this query then a PersistenceException is
-   * thrown.
-   * <p>
-   * This is useful when your predicates dictate that your query should only
-   * return 0 or 1 results.
+   * Execute the query returning a single bean or throwing a {@link jakarta.persistence.EntityNotFoundException}
+   * if there is no matching bean.
    * <p>
+   * This is a convenience alternative to:
    * <pre>{@code
-   *
-   * // assuming the sku of products is unique...
-   * Product product =
-   *     new QProduct()
-   *         .sku.equalTo("aa113")
-   *         .findOne();
-   * ...
+   *   query.findOneOrEmpty()
+   *     .orElseThrow(() -> new EntityNotFoundException(...));
    * }</pre>
    * <p>
-   * It is also useful with finding objects by their id when you want to specify
-   * further join information to optimise the query.
-   * <p>
-   * <pre>{@code
-   *
-   * // Fetch order 42 and additionally fetch join its order details...
-   * Order order =
-   *     new QOrder()
-   *         .fetch("details") // eagerly load the order details
-   *         .id.equalTo(42)
-   *         .findOne();
-   *
-   * // the order details were eagerly loaded
-   * List<OrderDetail> details = order.getDetails();
-   * ...
-   * }</pre>
+   * The exception message is a best effort - it uses the id when this is effectively a
+   * find-by-id query, or the single equality predicate when the query is filtered by what
+   * looks like a natural/unique key, otherwise a generic "not found" message.
    */
-  @Nullable
-  T findOne();
-
-  /**
-   * Execute the query returning an optional bean.
-   */
-  Optional<T> findOneOrEmpty();
-
-  /**
-   * Execute the query returning the list of objects.
-   * <p>
-   * This query will execute against the EbeanServer that was used to create it.
-   * <p>
-   * <pre>{@code
-   *
-   * List<Customer> customers =
-   *     new QCustomer()
-   *       .name.ilike("rob%")
-   *       .findList();
-   *
-   * }</pre>
-   *
-   * @see Query#findList()
-   */
-  List<T> findList();
-
-  /**
-   * Execute the query returning the result as a Stream.
-   * <p>
-   * Note that this can support very large queries iterating
-   * any number of results. To do so internally it can use
-   * multiple persistence contexts.
-   * </p>
-   * <pre>{@code
-   *
-   *  // use try with resources to ensure Stream is closed
-   *
-   *  try (Stream<Customer> stream = query.findStream()) {
-   *    stream
-   *    .map(...)
-   *    .collect(...);
-   *  }
-   *
-   * }</pre>
-   */
-  Stream<T> findStream();
+  @Override
+  default T findOneOrThrow() {
+    return findOneOrEmpty().orElseThrow(() ->
+      new EntityNotFoundException(getBeanType().getSimpleName() + " not found"));
+  }
 
   /**
    * Execute the query returning the set of objects.
@@ -864,84 +806,6 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
    */
   <A> Set<A> findSingleAttributeSet();
 
-  /**
-   * Execute the query processing the beans one at a time.
-   * <p>
-   * This method is appropriate to process very large query results as the
-   * beans are consumed one at a time and do not need to be held in memory
-   * (unlike #findList #findSet etc)
-   * <p>
-   * Note that internally Ebean can inform the JDBC driver that it is expecting larger
-   * resultSet and specifically for MySQL this hint is required to stop it's JDBC driver
-   * from buffering the entire resultSet. As such, for smaller resultSets findList() is
-   * generally preferable.
-   * <p>
-   * Compared with #findEachWhile this will always process all the beans where as
-   * #findEachWhile provides a way to stop processing the query result early before
-   * all the beans have been read.
-   * <p>
-   * This method is functionally equivalent to findIterate() but instead of using an
-   * iterator uses the Consumer interface which is better suited to use with closures.
-   *
-   * <pre>{@code
-   *
-   *  new QCustomer()
-   *     .status.equalTo(Status.NEW)
-   *     .orderBy().id.asc()
-   *     .findEach((Customer customer) -> {
-   *
-   *       // do something with customer
-   *       System.out.println("-- visit " + customer);
-   *     });
-   *
-   * }</pre>
-   *
-   * @param consumer the consumer used to process the queried beans.
-   */
-  void findEach(Consumer<T> consumer);
-
-  /**
-   * Execute findEach streaming query batching the results for consuming.
-   * <p>
-   * This query execution will stream the results and is suited to consuming
-   * large numbers of results from the database.
-   * <p>
-   * Typically, we use this batch consumer when we want to do further processing on
-   * the beans and want to do that processing in batch form, for example - 100 at
-   * a time.
-   *
-   * @param batch    The number of beans processed in the batch
-   * @param consumer Process the batch of beans
-   */
-  void findEach(int batch, Consumer<List<T>> consumer);
-
-  /**
-   * Execute the query using callbacks to a visitor to process the resulting
-   * beans one at a time.
-   * <p>
-   * This method is functionally equivalent to findIterate() but instead of using an
-   * iterator uses the Predicate interface which is better suited to use with closures.
-   *
-   * <pre>{@code
-   *
-   *  new QCustomer()
-   *     .status.equalTo(Status.NEW)
-   *     .orderBy().id.asc()
-   *     .findEachWhile((Customer customer) -> {
-   *
-   *       // do something with customer
-   *       System.out.println("-- visit " + customer);
-   *
-   *       // return true to continue processing or false to stop
-   *       return (customer.getId() < 40);
-   *     });
-   *
-   * }</pre>
-   *
-   * @param consumer the consumer used to process the queried beans.
-   */
-  void findEachWhile(Predicate<T> consumer);
-
   /**
    * Return versions of a @History entity bean.
    * <p>
@@ -1007,33 +871,4 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
    */
   <K> FutureMap<K,T> findFutureMap();
 
-  /**
-   * Return a PagedList for this query using firstRow and maxRows.
-   * <p>
-   * The benefit of using this over findList() is that it provides functionality to get the
-   * total row count etc.
-   * <p>
-   * If maxRows is not set on the query prior to calling findPagedList() then a
-   * PersistenceException is thrown.
-   * <p>
-   * <pre>{@code
-   *
-   *  PagedList<Order> pagedList =
-   *    new QOrder()
-   *       .setFirstRow(50)
-   *       .setMaxRows(20)
-   *       .findPagedList();
-   *
-   *       // fetch the total row count in the background
-   *       pagedList.loadRowCount();
-   *
-   *       List<Order> orders = pagedList.getList();
-   *       int totalRowCount = pagedList.getTotalRowCount();
-   *
-   * }</pre>
-   *
-   * @return The PagedList
-   */
-  PagedList<T> findPagedList();
-
 }

ebean-api/src/main/java/io/ebean/RawSqlBuilder.java

@@ -41,6 +41,49 @@ public interface RawSqlBuilder {
     return XBootstrapService.rawSql().unparsed(sql);
   }
 
+  /**
+   * Return a RawSqlBuilder for SQL containing {@code ${where}}, {@code ${having}} and/or
+   * {@code ${orderBy}} placeholder(s). Unlike {@link #parse(String)} this does NOT attempt to parse
+   * the SELECT columns, so it supports complex SQL such as CTEs, subqueries, and window functions.
+   * <p>
+   * Explicit column mappings must be provided (as with {@link #unparsed(String)}), but
+   * WHERE, HAVING and ORDER BY expressions can be added dynamically via the query API - provided
+   * the corresponding placeholder is present in the SQL. If a query calls {@code .orderBy(...)}
+   * on a template with no {@code ${orderBy}}/{@code ${andOrderBy}} placeholder, that ordering is
+   * ignored (there is no injection point for it) rather than producing invalid SQL.
+   * </p>
+   * <p>
+   * Available placeholders:
+   * </p>
+   * <ul>
+   *   <li>{@code ${where}} / {@code ${andWhere}} - inject "where &lt;expr&gt;" / "and &lt;expr&gt;"</li>
+   *   <li>{@code ${having}} / {@code ${andHaving}} - inject "having &lt;expr&gt;" / "and &lt;expr&gt;"</li>
+   *   <li>{@code ${orderBy}} / {@code ${andOrderBy}} - inject "order by &lt;expr&gt;" / ", &lt;expr&gt;"</li>
+   * </ul>
+   * <h3>Example:</h3>
+   * <pre>{@code
+   *
+   *   String sql = """
+   *     with agg as (
+   *       select company_id, sum(amount) as total
+   *       from orders
+   *       ${where}
+   *       group by company_id
+   *     )
+   *     select company_id, total from agg ${orderBy}
+   *     """;
+   *
+   *   RawSql rawSql = RawSqlBuilder.withPlaceholders(sql)
+   *     .columnMapping("company_id", "companyId")
+   *     .columnMapping("total", "total")
+   *     .create();
+   *
+   * }</pre>
+   */
+  static RawSqlBuilder withPlaceholders(String sql) {
+    return XBootstrapService.rawSql().withPlaceholders(sql);
+  }
+
   /**
    * Return a RawSqlBuilder parsing the sql.
    * <p>

ebean-api/src/main/java/io/ebean/SqlQuery.java

@@ -3,7 +3,6 @@ package io.ebean;
 import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
-import javax.sql.DataSource;
 import java.io.Serializable;
 import java.sql.Connection;
 import java.util.Collection;
@@ -41,44 +40,7 @@ import java.util.function.Predicate;
  * }</pre>
  */
 @NullMarked
-public interface SqlQuery extends Serializable, CancelableQuery {
-
-  /**
-   * Execute the query using the given transaction.
-   */
-  SqlQuery usingTransaction(Transaction transaction);
-
-  /**
-   * Execute the query using the given connection.
-   */
-  SqlQuery usingConnection(Connection connection);
-
-  /**
-   * Ensure that the master DataSource is used if there is a read only data source
-   * being used (that is using a read replica database potentially with replication lag).
-   * <p>
-   * When the database is configured with a read-only DataSource via
-   * say {@link io.ebean.DatabaseBuilder#readOnlyDataSource(DataSource)}then
-   * by default when a query is run without an active transaction, it uses the read-only data
-   * source. We use {@code usingMaster()} to instead ensure that the query is executed
-   * against the master data source.
-   */
-  default SqlQuery usingMaster() {
-    return usingMaster(true);
-  }
-
-  /**
-   * Ensure the master DataSource is used when useMaster is true. Otherwise, the read only
-   * data source can be used if defined.
-   *
-   * @see #usingMaster()
-   */
-  SqlQuery usingMaster(boolean useMaster);
-
-  /**
-   * Execute the query returning a list.
-   */
-  List<SqlRow> findList();
+public interface SqlQuery extends Serializable, FindableQuery<SqlQuery, SqlRow> {
 
   /**
    * Execute the SqlQuery iterating a row at a time.
@@ -99,16 +61,6 @@ public interface SqlQuery extends Serializable, CancelableQuery {
    */
   void findEachWhile(Predicate<SqlRow> consumer);
 
-  /**
-   * Execute the query returning a single row or null.
-   * <p>
-   * If this query finds 2 or more rows then it will throw a
-   * PersistenceException.
-   * </p>
-   */
-  @Nullable
-  SqlRow findOne();
-
   /**
    * Execute the query reading each row from ResultSet using the RowConsumer.
    * <p>
@@ -139,11 +91,6 @@ public interface SqlQuery extends Serializable, CancelableQuery {
    */
   void findEachRow(RowConsumer consumer);
 
-  /**
-   * Execute the query returning an optional row.
-   */
-  Optional<SqlRow> findOneOrEmpty();
-
   /**
    * Set one of more positioned parameters.
    * <p>
@@ -365,7 +312,7 @@ public interface SqlQuery extends Serializable, CancelableQuery {
    *
    * @param <T> The type of the scalar values
    */
-  interface TypeQuery<T> {
+  interface TypeQuery<T> extends FindableQuery<TypeQuery<T>, T> {
 
     /**
      * Ensure the master DataSource is used when useMaster is true. Otherwise, the read only
@@ -373,27 +320,38 @@ public interface SqlQuery extends Serializable, CancelableQuery {
      *
      * @see SqlQuery#usingMaster(boolean)
      */
+    @Override
     TypeQuery<T> usingMaster(boolean useMaster);
 
     /**
      * Execute the query using the given transaction.
      */
+    @Override
     TypeQuery<T> usingTransaction(Transaction transaction);
 
+    /**
+     * Execute the query using the given connection.
+     */
+    @Override
+    TypeQuery<T> usingConnection(Connection connection);
+
     /**
      * Return the single value.
      */
     @Nullable
+    @Override
     T findOne();
 
     /**
      * Return the single value that is optional.
      */
+    @Override
     Optional<T> findOneOrEmpty();
 
     /**
      * Return the list of values.
      */
+    @Override
     List<T> findList();
 
     /**

ebean-api/src/main/java/io/ebean/SqlUpdate.java

@@ -158,6 +158,15 @@ public interface SqlUpdate {
    */
   int executeNow();
 
+  /**
+   * Set an explicit transaction to use to execute this statement.
+   * <p>
+   * When not set, {@link #execute()} and {@link #executeNow()} use whatever transaction
+   * is currently active on the thread (or auto-commit if none is active) - consistent
+   * with {@link Database#execute(SqlUpdate, Transaction)}.
+   */
+  SqlUpdate usingTransaction(Transaction transaction);
+
   /**
    * Execute when addBatch() has been used to batch multiple bind executions.
    *

ebean-api/src/main/java/io/ebean/StreamableQuery.java

@@ -0,0 +1,101 @@
+package io.ebean;
+
+import org.jspecify.annotations.NullMarked;
+
+import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+
+/**
+ * A {@link FindableQuery} that additionally supports streaming results and paging.
+ *
+ * @param <SELF> The query type (used for method chaining)
+ * @param <T>    The type of the result
+ */
+@NullMarked
+public interface StreamableQuery<SELF extends StreamableQuery<SELF, T>, T> extends FindableQuery<SELF, T> {
+
+  /**
+   * Execute the query returning the result as a Stream.
+   * <p>
+   * Note that this can support very large queries iterating any number of results.
+   * To do so internally it can use multiple persistence contexts.
+   * <p>
+   * Note that the Stream holds resources related to the underlying resultSet and
+   * potentially connection and MUST be closed. We should use the Stream in a
+   * <em>try with resource block</em>.
+   * <pre>{@code
+   *
+   *  // use try with resources to ensure Stream is closed
+   *
+   *  try (Stream<T> stream = query.findStream()) {
+   *    stream
+   *    .map(...)
+   *    .collect(...);
+   *  }
+   *
+   * }</pre>
+   */
+  Stream<T> findStream();
+
+  /**
+   * Return a PagedList for this query using firstRow and maxRows.
+   * <p>
+   * The benefit of using this over findList() is that it provides functionality to get the
+   * total row count etc.
+   * <p>
+   * If maxRows is not set on the query prior to calling findPagedList() then a
+   * PersistenceException is thrown.
+   *
+   * @return The PagedList
+   */
+  PagedList<T> findPagedList();
+
+  /**
+   * Execute the query processing the results one at a time.
+   * <p>
+   * This method is appropriate to process very large query results as the results are
+   * consumed one at a time and do not need to be held in memory (unlike {@link #findList()}).
+   * <p>
+   * Note that internally Ebean can inform the JDBC driver that it is expecting a larger
+   * resultSet and specifically for MySQL this hint is required to stop its JDBC driver
+   * from buffering the entire resultSet. As such, for smaller resultSets findList() is
+   * generally preferable.
+   * <p>
+   * Compared with {@link #findEachWhile(Predicate)} this will always process all the results
+   * whereas findEachWhile() provides a way to stop processing the query result early before
+   * all the results have been read.
+   *
+   * @param consumer the consumer used to process the queried results.
+   */
+  void findEach(Consumer<T> consumer);
+
+  /**
+   * Execute findEach streaming query batching the results for consuming.
+   * <p>
+   * This query execution will stream the results and is suited to consuming
+   * large numbers of results from the database.
+   * <p>
+   * Typically, we use this batch consumer when we want to do further processing on
+   * the results and want to do that processing in batch form, for example - 100 at
+   * a time.
+   *
+   * @param batch    The number of results processed in the batch
+   * @param consumer Process the batch of results
+   */
+  void findEach(int batch, Consumer<List<T>> consumer);
+
+  /**
+   * Execute the query using callbacks to process the resulting results one at a time,
+   * with the ability to stop processing part way through.
+   * <p>
+   * Returning {@code false} after processing a result stops the iteration through the
+   * query results.
+   *
+   * @param consumer the consumer used to process the queried results, returning
+   *                 {@code false} to stop processing.
+   */
+  void findEachWhile(Predicate<T> consumer);
+
+}

ebean-api/src/main/java/io/ebean/Update.java

@@ -84,6 +84,15 @@ public interface Update<T> {
    */
   int execute();
 
+  /**
+   * Set an explicit transaction to use to execute this statement.
+   * <p>
+   * When not set, {@link #execute()} uses whatever transaction is currently active on
+   * the thread (or auto-commit if none is active) - consistent with
+   * {@link Database#execute(Update, Transaction)}.
+   */
+  Update<T> usingTransaction(Transaction transaction);
+
   /**
    * Set an ordered bind parameter.
    * <p>

ebean-api/src/main/java/io/ebean/bean/InterceptReadOnly.java

@@ -175,7 +175,7 @@ public final class InterceptReadOnly extends InterceptBase {
 
   @Override
   public boolean isUpdate() {
-    return false;
+    return true;
   }
 
   @Override

ebean-api/src/main/java/io/ebean/config/DatabaseConfig.java

@@ -432,6 +432,8 @@ public class DatabaseConfig implements DatabaseBuilder.Settings {
   private int backgroundExecutorShutdownSecs = 30;
   private BackgroundExecutorWrapper backgroundExecutorWrapper = new MdcBackgroundExecutorWrapper();
 
+  private boolean tenantPartitionedCache;
+
   // defaults for the L2 bean caching
 
   private int cacheMaxSize = 10000;
@@ -1175,6 +1177,17 @@ public class DatabaseConfig implements DatabaseBuilder.Settings {
     return cacheMaxSize;
   }
 
+  @Override
+  public boolean isTenantPartitionedCache() {
+    return tenantPartitionedCache;
+  }
+
+  @Override
+  public DatabaseConfig tenantPartitionedCache(boolean tenantPartitionedCache) {
+    this.tenantPartitionedCache = tenantPartitionedCache;
+    return this;
+  }
+
   @Override
   public DatabaseConfig setCacheMaxSize(int cacheMaxSize) {
     this.cacheMaxSize = cacheMaxSize;
@@ -2228,6 +2241,15 @@ public class DatabaseConfig implements DatabaseBuilder.Settings {
     ddlPlaceholders = p.get("ddl.placeholders", ddlPlaceholders);
     ddlHeader = p.get("ddl.header", ddlHeader);
 
+    tenantPartitionedCache = p.getBoolean("tenantPartitionedCache", tenantPartitionedCache);
+
+    cacheMaxSize = p.getInt("cacheMaxSize", cacheMaxSize);
+    cacheMaxIdleTime = p.getInt("cacheMaxIdleTime", cacheMaxIdleTime);
+    cacheMaxTimeToLive = p.getInt("cacheMaxTimeToLive", cacheMaxTimeToLive);
+    queryCacheMaxSize = p.getInt("queryCacheMaxSize", queryCacheMaxSize);
+    queryCacheMaxIdleTime = p.getInt("queryCacheMaxIdleTime", queryCacheMaxIdleTime);
+    queryCacheMaxTimeToLive = p.getInt("queryCacheMaxTimeToLive", queryCacheMaxTimeToLive);
+
     // read tenant-configuration from config:
     // tenant.mode = NONE | DB | SCHEMA | CATALOG | PARTITION
     String mode = p.get("tenant.mode");

ebean-api/src/main/java/io/ebean/config/DtoMapperRegister.java

@@ -0,0 +1,31 @@
+package io.ebean.config;
+
+import io.ebean.DtoMapper;
+
+/**
+ * Loads and returns the {@link DtoMapper} to use for a given DTO type, generated per-module by
+ * the querybean-generator annotation processor for each {@code io.ebean.annotation.DtoMapping}
+ * registered pair.
+ * <p>
+ * Implementations resolve purely via literal {@code Class} comparisons (no reflection,
+ * {@code Class.forName}, or {@code MethodHandles}) - safe under GraalVM native-image with zero
+ * additional reachability metadata - mirroring {@link EntityClassRegister}.
+ */
+public interface DtoMapperRegister {
+
+  /**
+   * Return the mapper for the given DTO type, or {@code null} if this register has no mapper for
+   * that type.
+   */
+  <SOURCE,TARGET> DtoMapper<SOURCE, TARGET> mapperFor(Class<SOURCE> sourceType, Class<TARGET> targetType);
+
+  /**
+   * Return the mapper instance of the given concrete generated mapper type, or {@code null} if
+   * this register has no mapper of that type.
+   * <p>
+   * An alternative to {@link #mapperFor(Class, Class)} for looking up a mapper by its own class
+   * (e.g. {@code CustomerDtoMapper.class}) rather than by its (source, target) pair - typically
+   * used to resolve a mapper instance for dependency injection into application code.
+   */
+  <T> T mapperOfType(Class<T> mapperType);
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/DatabasePlatform.java

@@ -162,6 +162,18 @@ public class DatabasePlatform {
   protected boolean selectCountWithAlias;
   protected boolean selectCountWithColumnAlias;
 
+  /**
+   * Set true for platforms where {@code exists(...)} can only be used as a predicate
+   * and not as a directly selectable scalar boolean expression (e.g. SQL Server, Oracle).
+   */
+  protected boolean existsWithCaseWhen;
+
+  /**
+   * Clause appended after the {@code case when exists(...) then 1 else 0 end} exists query
+   * for platforms that require a FROM clause on every select (e.g. {@code from dual} on Oracle).
+   */
+  protected String existsFromClause = "";
+
   /**
    * If set then use the FORWARD ONLY hint when creating ResultSets for
    * findIterate() and findVisit().
@@ -660,6 +672,21 @@ public class DatabasePlatform {
     return selectCountWithColumnAlias;
   }
 
+  /**
+   * Return true if a scalar boolean {@code exists(...)} expression is not supported
+   * as a select expression and needs to be wrapped as {@code case when exists(...) then 1 else 0 end}.
+   */
+  public boolean existsWithCaseWhen() {
+    return existsWithCaseWhen;
+  }
+
+  /**
+   * Return the clause to append after the exists case-when wrapping (e.g. {@code from dual} on Oracle).
+   */
+  public String existsFromClause() {
+    return existsFromClause;
+  }
+
 
   public String completeSql(String sql, Query<?> query) {
     if (query.isForUpdate()) {

ebean-api/src/main/java/io/ebean/event/ShutdownManager.java

@@ -1,6 +1,7 @@
 package io.ebean.event;
 
 import io.ebean.Database;
+import io.ebean.DatabaseFactory;
 import io.ebean.EbeanVersion;
 import io.ebean.service.SpiContainer;
 
@@ -188,6 +189,7 @@ public final class ShutdownManager {
    */
   public static void unregisterDatabase(Database server) {
     databases.remove(server);
+    DatabaseFactory.unregister(server);
   }
 
   private static class ShutdownHook extends Thread {

ebean-api/src/main/java/io/ebean/meta/MetaQueryPlan.java

@@ -44,6 +44,11 @@ public interface MetaQueryPlan {
    */
   String plan();
 
+  /**
+   * The tenant ID of the plan.
+   */
+  Object tenantId();
+
   /**
    * Return the query execution time associated with the bind values capture.
    */

ebean-api/src/main/java/io/ebean/service/SpiRawSqlService.java

@@ -27,6 +27,13 @@ public interface SpiRawSqlService extends BootstrapService {
    */
   RawSqlBuilder unparsed(String sql);
 
+  /**
+   * SQL with ${where}/${having} placeholder(s) but no SELECT column parsing.
+   * Supports complex SQL (CTEs, window functions) where keyword parsing would fail.
+   * Explicit column mapping is required (as with unparsed).
+   */
+  RawSqlBuilder withPlaceholders(String sql);
+
   /**
    * Create based on a JDBC ResultSet.
    *

ebean-bench/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
 
   <artifactId>ebean-bench</artifactId>

ebean-bom/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
 
   <name>ebean bom</name>
@@ -89,25 +89,25 @@
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-api</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-core</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-core-type</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
@@ -125,13 +125,13 @@
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-jackson-mapper</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-ddl-generator</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
@@ -155,37 +155,37 @@
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-querybean</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>querybean-generator</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>kotlin-querybean-generator</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-test</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-redis</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-spring-txn</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <!-- platforms -->
@@ -193,91 +193,91 @@
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-clickhouse</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-db2</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-h2</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-hana</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-mariadb</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-mysql</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-nuodb</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-oracle</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-postgres</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-postgis</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-postgis-types</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-pgvector</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-pgvector-types</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-sqlite</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
       <dependency>
         <groupId>io.ebean</groupId>
         <artifactId>ebean-sqlserver</artifactId>
-        <version>18.1.0</version>
+        <version>18.3.0</version>
       </dependency>
 
     </dependencies>

ebean-core-json/pom.xml

@@ -3,7 +3,7 @@
   <parent>
     <groupId>io.ebean</groupId>
     <artifactId>ebean-parent</artifactId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
   <artifactId>ebean-core-json</artifactId>
   <name>ebean-core-json</name>
@@ -16,7 +16,7 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>

ebean-core-type/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
 
   <artifactId>ebean-core-type</artifactId>
@@ -16,7 +16,7 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -29,7 +29,7 @@
     <dependency>
       <groupId>org.postgresql</groupId>
       <artifactId>postgresql</artifactId>
-      <version>42.7.2</version>
+      <version>42.7.11</version>
       <optional>true</optional>
     </dependency>
 

ebean-core/pom.xml

@@ -3,7 +3,7 @@
   <parent>
     <artifactId>ebean-parent</artifactId>
     <groupId>io.ebean</groupId>
-    <version>18.1.0</version>
+    <version>18.3.0</version>
   </parent>
 
   <artifactId>ebean-core</artifactId>
@@ -22,13 +22,13 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-api</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core-json</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -52,7 +52,7 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-core-type</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
     </dependency>
 
     <dependency>
@@ -149,7 +149,7 @@
     <dependency>
       <groupId>org.postgresql</groupId>
       <artifactId>postgresql</artifactId>
-      <version>42.7.2</version>
+      <version>42.7.11</version>
       <optional>true</optional>
     </dependency>
 
@@ -157,21 +157,21 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-h2</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
       <scope>test</scope>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-postgres</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
       <scope>test</scope>
     </dependency>
 
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-platform-sqlserver</artifactId>
-      <version>18.1.0</version>
+      <version>18.3.0</version>
       <scope>test</scope>
     </dependency>
 

ebean-core/src/main/java/io/ebeaninternal/api/LoadBeanRequest.java

@@ -100,7 +100,9 @@ public final class LoadBeanRequest extends LoadRequest {
     query.setLoadDescription(mode(), description());
     if (lazy) {
       query.setLazyLoadBatchSize(loadBuffer.batchSize());
-      if (alreadyLoaded) {
+      if (alreadyLoaded || !loadCache) {
+        // alreadyLoaded: bean is being re-loaded, skip the cache to avoid a stale hit
+        // !loadCache: parent context disabled cache (e.g. CacheMode.OFF or asOf query),
         query.setBeanCacheMode(CacheMode.OFF);
       }
     } else {

ebean-core/src/main/java/io/ebeaninternal/api/SpiDbQueryPlan.java

@@ -12,6 +12,6 @@ public interface SpiDbQueryPlan extends MetaQueryPlan {
   /**
    * Extend with queryTimeMicros, captureCount, captureMicros and when the bind values were captured.
    */
-  SpiDbQueryPlan with(long queryTimeMicros, long captureCount, long captureMicros, Instant whenCaptured);
+  SpiDbQueryPlan with(long queryTimeMicros, long captureCount, long captureMicros, Instant whenCaptured, Object tenantId);
 
 }

ebean-core/src/main/java/io/ebeaninternal/api/SpiEbeanServer.java

@@ -294,6 +294,16 @@ public interface SpiEbeanServer extends SpiServer, BeanCollectionLoader {
    */
   <D> DtoQuery<D> findDto(Class<D> dtoType, SpiQuery<?> ormQuery);
 
+  /**
+   * Return the generated {@link DtoMapper} for mapping the given source entity type to the given
+   * DTO type, discovered (via {@code ServiceLoader}) from the {@code DtoMapperRegister}s
+   * generated by {@code querybean-generator} - used by {@code query.mapTo(dtoType)}.
+   *
+   * @throws jakarta.persistence.PersistenceException if no mapper is registered for that
+   *     (source, dto) pair.
+   */
+  <S, D> DtoMapper<S, D> dtoMapper(Class<S> sourceType, Class<D> dtoType);
+
   /**
    * Execute the underlying ORM query returning as a JDBC ResultSet to map to DTO beans.
    */
@@ -324,6 +334,12 @@ public interface SpiEbeanServer extends SpiServer, BeanCollectionLoader {
    */
   int executeNow(SpiSqlUpdate sqlUpdate);
 
+  /**
+   * Execute the sql update regardless of transaction batch mode using the given
+   * explicit transaction (or the current ambient transaction when null).
+   */
+  int executeNow(SpiSqlUpdate sqlUpdate, @Nullable Transaction transaction);
+
   /**
    * Create a query bind capture for the given query plan.
    */
@@ -374,6 +390,8 @@ public interface SpiEbeanServer extends SpiServer, BeanCollectionLoader {
 
   <T> int delete(SpiQuery<T> query);
 
+  <T> int deletePermanent(SpiQuery<T> query);
+
   <T> int update(SpiQuery<T> query);
 
   List<SqlRow> findList(SpiSqlQuery query);

ebean-core/src/main/java/io/ebeaninternal/api/SpiExpressionValidation.java

@@ -12,6 +12,7 @@ public final class SpiExpressionValidation {
 
   private final BeanType<?> desc;
   private final LinkedHashSet<String> unknown = new LinkedHashSet<>();
+  private final LinkedHashSet<String> all = new LinkedHashSet<>();
 
   public SpiExpressionValidation(BeanType<?> desc) {
     this.desc = desc;
@@ -21,6 +22,7 @@ public final class SpiExpressionValidation {
    * Validate that the property expression (path) is valid.
    */
   public void validate(String propertyName) {
+    all.add(propertyName);
     if (!desc.isValidExpression(propertyName)) {
       unknown.add(propertyName);
     }
@@ -33,4 +35,14 @@ public final class SpiExpressionValidation {
     return unknown;
   }
 
+  /**
+   * Return the set of all property names visited during this validation, regardless of
+   * whether they were considered valid against the bean type. Used to inspect the shape of
+   * an expression (for example, to check whether it references any associated/joined path)
+   * without needing a correctly-typed bean descriptor.
+   */
+  public Set<String> allProperties() {
+    return all;
+  }
+
 }

ebean-core/src/main/java/io/ebeaninternal/api/SpiQueryManyJoin.java

@@ -15,4 +15,19 @@ public interface SpiQueryManyJoin {
    */
   String fetchOrderBy();
 
+  /**
+   * Return true if this many relationship has an order column stored on the
+   * ManyToMany intersection table (rather than a target descriptor property).
+   */
+  default boolean hasIntersectionOrderColumn() {
+    return false;
+  }
+
+  /**
+   * Return the db column name of the ManyToMany intersection table order column (or null).
+   */
+  default String intersectionOrderColumn() {
+    return null;
+  }
+
 }

ebean-core/src/main/java/io/ebeaninternal/api/SpiTransactionManager.java

@@ -60,6 +60,6 @@ public interface SpiTransactionManager {
   /**
    * Return a connection used for query plan collection.
    */
-  Connection queryPlanConnection() throws SQLException;
+  Connection queryPlanConnection(Object tenantId) throws SQLException;
 
 }

ebean-core/src/main/java/io/ebeaninternal/server/cache/CacheManagerOptions.java

@@ -13,8 +13,9 @@ import io.ebeaninternal.server.cluster.ClusterManager;
 public final class CacheManagerOptions {
 
   private final ClusterManager clusterManager;
-  private final DatabaseBuilder.Settings databaseBuilder;
+  private final String serverName;
   private final boolean localL2Caching;
+  private final boolean tenantPartitionedCache;
   private CurrentTenantProvider currentTenantProvider;
   private QueryCacheEntryValidate queryCacheEntryValidate;
   private ServerCacheFactory cacheFactory = new DefaultServerCacheFactory();
@@ -24,7 +25,8 @@ public final class CacheManagerOptions {
   CacheManagerOptions() {
     this.localL2Caching = true;
     this.clusterManager = null;
-    this.databaseBuilder = null;
+    this.serverName = "db";
+    this.tenantPartitionedCache = false;
     this.cacheFactory = new DefaultServerCacheFactory();
     this.beanDefault = new ServerCacheOptions();
     this.queryDefault = new ServerCacheOptions();
@@ -32,9 +34,10 @@ public final class CacheManagerOptions {
 
   public CacheManagerOptions(ClusterManager clusterManager, DatabaseBuilder.Settings config, boolean localL2Caching) {
     this.clusterManager = clusterManager;
-    this.databaseBuilder = config;
+    this.serverName = config.getName();
     this.localL2Caching = localL2Caching;
     this.currentTenantProvider = config.getCurrentTenantProvider();
+    this.tenantPartitionedCache = config.isTenantPartitionedCache();
   }
 
   public CacheManagerOptions with(ServerCacheOptions beanDefault, ServerCacheOptions queryDefault) {
@@ -55,7 +58,7 @@ public final class CacheManagerOptions {
   }
 
   public String getServerName() {
-    return (databaseBuilder == null) ? "db" : databaseBuilder.getName();
+    return serverName;
   }
 
   public boolean isLocalL2Caching() {
@@ -85,4 +88,8 @@ public final class CacheManagerOptions {
   public QueryCacheEntryValidate getQueryCacheEntryValidate() {
     return queryCacheEntryValidate;
   }
+
+  public boolean isTenantPartitionedCache() {
+    return tenantPartitionedCache;
+  }
 }

ebean-core/src/main/java/io/ebeaninternal/server/cache/DefaultCacheHolder.java

@@ -9,6 +9,7 @@ import io.ebean.config.CurrentTenantProvider;
 import io.ebean.meta.MetricVisitor;
 import io.ebean.util.AnnotationUtil;
 
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentSkipListSet;
@@ -32,6 +33,7 @@ final class DefaultCacheHolder {
   private final ServerCacheOptions queryDefault;
   private final CurrentTenantProvider tenantProvider;
   private final QueryCacheEntryValidate queryCacheEntryValidate;
+  private final boolean tenantPartitionedCache;
 
   DefaultCacheHolder(CacheManagerOptions builder) {
     this.cacheFactory = builder.getCacheFactory();
@@ -39,6 +41,7 @@ final class DefaultCacheHolder {
     this.queryDefault = builder.getQueryDefault();
     this.tenantProvider = builder.getCurrentTenantProvider();
     this.queryCacheEntryValidate = builder.getQueryCacheEntryValidate();
+    this.tenantPartitionedCache = builder.isTenantPartitionedCache();
   }
 
   void visitMetrics(MetricVisitor visitor) {
@@ -56,16 +59,31 @@ final class DefaultCacheHolder {
     return getCacheInternal(beanType, ServerCacheType.COLLECTION_IDS, collectionProperty);
   }
 
+  private String tenantKey(String beanName) {
+    if (tenantPartitionedCache) {
+      return beanName + '.' + tenantProvider.currentId();
+    }
+    return beanName;
+  }
+
   private String key(String beanName, ServerCacheType type) {
+    if (tenantPartitionedCache) {
+      return beanName + '.' + tenantProvider.currentId() + type.code();
+    }
     return beanName + type.code();
   }
 
   private String key(String beanName, String collectionProperty, ServerCacheType type) {
-    if (collectionProperty != null) {
-      return beanName + "." + collectionProperty + type.code();
-    } else {
-      return beanName + type.code();
+    StringBuilder sb = new StringBuilder(beanName.length() + 64);
+    sb.append(beanName);
+    if (tenantPartitionedCache) {
+      sb.append('.').append(tenantProvider.currentId());
     }
+    if (collectionProperty != null) {
+      sb.append('.').append(collectionProperty);
+    }
+    sb.append(type.code());
+    return sb.toString();
   }
 
   /**
@@ -82,12 +100,15 @@ final class DefaultCacheHolder {
     if (type == ServerCacheType.COLLECTION_IDS) {
       lock.lock();
       try {
-        collectIdCaches.computeIfAbsent(beanType.getName(), s -> new ConcurrentSkipListSet<>()).add(key);
+        collectIdCaches.computeIfAbsent(tenantKey(beanType.getName()), s -> new ConcurrentSkipListSet<>()).add(key);
       } finally {
         lock.unlock();
       }
     }
-    return cacheFactory.createCache(new ServerCacheConfig(type, key, shortName, options, tenantProvider, queryCacheEntryValidate));
+    // in partitioned mode each ServerCache instance is already tenant-scoped via its key,
+    // so the tenantProvider is not needed inside the cache itself
+    CurrentTenantProvider cacheProvider = tenantPartitionedCache ? null : tenantProvider;
+    return cacheFactory.createCache(new ServerCacheConfig(type, key, shortName, options, cacheProvider, queryCacheEntryValidate));
   }
 
   void clearAll() {
@@ -100,17 +121,75 @@ final class DefaultCacheHolder {
 
   public void clear(String name) {
     log.log(DEBUG, "clear {0}", name);
-    clearIfExists(key(name, ServerCacheType.QUERY));
-    clearIfExists(key(name, ServerCacheType.BEAN));
-    clearIfExists(key(name, ServerCacheType.NATURAL_KEY));
-    Set<String> keys = collectIdCaches.get(name);
-    if (keys != null) {
-      for (String collectionIdKey : keys) {
-        clearIfExists(collectionIdKey);
+    if (tenantPartitionedCache) {
+      // In partitioned mode, tenantProvider.currentId() may be null/wrong on a background
+      // invalidation thread. Scan all cache entries for this entity type across all tenants.
+      clearAllTenantsFor(name);
+    } else {
+      clearIfExists(key(name, ServerCacheType.QUERY));
+      clearIfExists(key(name, ServerCacheType.BEAN));
+      clearIfExists(key(name, ServerCacheType.NATURAL_KEY));
+      Set<String> keys = collectIdCaches.get(name);
+      if (keys != null) {
+        for (String collectionIdKey : keys) {
+          clearIfExists(collectionIdKey);
+        }
       }
     }
   }
 
+  private void clearAllTenantsFor(String name) {
+    // Keys in partitioned mode: beanName.tenantId_X or beanName.tenantId.prop_X
+    // collectIdCaches keys: beanName.tenantId
+    // Both start with beanName + '.' so we can use prefix scan.
+    String prefix = name + '.';
+    for (Map.Entry<String, ServerCache> entry : allCaches.entrySet()) {
+      if (entry.getKey().startsWith(prefix)) {
+        log.log(TRACE, "clear cache {0}", entry.getKey());
+        entry.getValue().clear();
+      }
+    }
+    lock.lock();
+    try {
+      for (Map.Entry<String, Set<String>> entry : collectIdCaches.entrySet()) {
+        if (entry.getKey().startsWith(prefix)) {
+          for (String collectionIdKey : entry.getValue()) {
+            clearIfExists(collectionIdKey);
+          }
+        }
+      }
+    } finally {
+      lock.unlock();
+    }
+  }
+
+  /**
+   * Remove all cache entries belonging to the given tenant.
+   * Call this when a tenant is deactivated to prevent unbounded memory growth.
+   */
+  void clearTenant(Object tenantId) {
+    String tenantIdStr = String.valueOf(tenantId);
+    // Keys look like: beanName.tenantId_X  or  beanName.tenantId.prop_X
+    String segmentBeforeTypeCode = '.' + tenantIdStr + '_';
+    String segmentBeforeProperty = '.' + tenantIdStr + '.';
+    allCaches.entrySet().removeIf(e -> {
+      String k = e.getKey();
+      return k.contains(segmentBeforeTypeCode) || k.contains(segmentBeforeProperty);
+    });
+    // collectIdCaches keys look like: beanName.tenantId
+    String collectKeySuffix = '.' + tenantIdStr;
+    lock.lock();
+    try {
+      collectIdCaches.entrySet().removeIf(e -> e.getKey().endsWith(collectKeySuffix));
+    } finally {
+      lock.unlock();
+    }
+  }
+
+  boolean isTenantPartitionedCache() {
+    return tenantPartitionedCache;
+  }
+
   private void clearIfExists(String fullKey) {
     ServerCache cache = allCaches.get(fullKey);
     if (cache != null) {

ebean-core/src/main/java/io/ebeaninternal/server/cache/DefaultServerCacheManager.java

@@ -154,4 +154,14 @@ public final class DefaultServerCacheManager implements SpiCacheManager {
     return cacheHolder.getCache(beanType, ServerCacheType.BEAN);
   }
 
+  @Override
+  public boolean isTenantPartitionedCache() {
+    return cacheHolder.isTenantPartitionedCache();
+  }
+
+  @Override
+  public void clearTenant(Object tenantId) {
+    cacheHolder.clearTenant(tenantId);
+  }
+
 }

ebean-core/src/main/java/io/ebeaninternal/server/cache/SpiCacheManager.java

@@ -88,4 +88,17 @@ public interface SpiCacheManager {
    */
   void clearLocal(Class<?> beanType);
 
+  /**
+   * Returns true if this cache manager runs in tenant-partitioned mode.
+   * In this mode caches are namespaced per tenant to improve cache-hit ratio.
+   */
+  boolean isTenantPartitionedCache();
+
+  /**
+   * Remove all cache entries belonging to the given tenant.
+   * Call this when a tenant is deactivated to prevent unbounded memory growth
+   * in tenant-partitioned mode.
+   */
+  void clearTenant(Object tenantId);
+
 }

ebean-core/src/main/java/io/ebeaninternal/server/core/DefaultServer.java

@@ -90,6 +90,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
   private final DtoQueryEngine dtoQueryEngine;
   private final ServerCacheManager serverCacheManager;
   private final DtoBeanManager dtoBeanManager;
+  private final DtoMapperManager dtoMapperManager;
   private final BeanDescriptorManager descriptorManager;
   private final AutoTuneService autoTuneService;
   private final ReadAuditPrepare readAuditPrepare;
@@ -122,6 +123,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
   public DefaultServer(InternalConfiguration config, ServerCacheManager cache) {
     this.logManager = config.getLogManager();
     this.dtoBeanManager = config.getDtoBeanManager();
+    this.dtoMapperManager = config.getDtoMapperManager();
     this.config = config.getConfig();
     this.disableL2Cache = this.config.isDisableL2Cache();
     this.serverCacheManager = cache;
@@ -899,6 +901,11 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
     return new DefaultDtoQuery<>(this, descriptor, ormQuery);
   }
 
+  @Override
+  public <S, D> DtoMapper<S, D> dtoMapper(Class<S> sourceType, Class<D> dtoType) {
+    return dtoMapperManager.mapperFor(sourceType, dtoType);
+  }
+
   @Override
   public SpiResultSet findResultSet(SpiQuery<?> ormQuery) {
     SpiOrmQueryRequest<?> request = createQueryRequest(ormQuery.type(), ormQuery);
@@ -1197,15 +1204,14 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
   @Override
   public <T> boolean exists(SpiQuery<T> ormQuery) {
     SpiQuery<T> ormQueryCopy = ormQuery.copy();
-    ormQueryCopy.setMaxRows(1);
     SpiOrmQueryRequest<?> request = createQueryRequest(Type.EXISTS, ormQueryCopy);
-    List<Object> ids = request.getFromQueryCache();
-    if (ids != null) {
-      return !ids.isEmpty();
+    Object cached = request.getFromQueryCache();
+    if (cached != null) {
+      return (Boolean) cached;
     }
     try {
       request.initTransIfRequired();
-      return !request.findIds().isEmpty();
+      return request.findExists();
     } finally {
       request.endTransIfRequired();
     }
@@ -1234,6 +1240,15 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
 
   @Override
   public <T> int delete(SpiQuery<T> query) {
+    return delete(query, false);
+  }
+
+  @Override
+  public <T> int deletePermanent(SpiQuery<T> query) {
+    return delete(query, true);
+  }
+
+  private <T> int delete(SpiQuery<T> query, boolean permanent) {
     SpiOrmQueryRequest<T> request = createQueryRequest(Type.DELETE, query);
     try {
       request.initTransIfRequired();
@@ -1247,7 +1262,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
         if (ids.isEmpty()) {
           return 0;
         } else {
-          return persister.deleteByIds(request.descriptor(), ids, request.transaction(), false);
+          return persister.deleteByIds(request.descriptor(), ids, request.transaction(), permanent);
         }
       }
     } finally {
@@ -1923,7 +1938,12 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
 
   @Override
   public int executeNow(SpiSqlUpdate sqlUpdate) {
-    return persister.executeSqlUpdateNow(sqlUpdate, null);
+    return executeNow(sqlUpdate, null);
+  }
+
+  @Override
+  public int executeNow(SpiSqlUpdate sqlUpdate, @Nullable Transaction transaction) {
+    return persister.executeSqlUpdateNow(sqlUpdate, transaction);
   }
 
   @Override
@@ -2188,12 +2208,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
   }
 
   @Override
-  public Set<Property> checkUniqueness(Object bean) {
-    return checkUniqueness(bean, null);
-  }
-
-  @Override
-  public Set<Property> checkUniqueness(Object bean, @Nullable Transaction transaction) {
+  public Set<Property> checkUniqueness(Object bean, @Nullable Transaction transaction, boolean useQueryCache, boolean skipClean) {
     EntityBean entityBean = checkEntityBean(bean);
     BeanDescriptor<?> beanDesc = descriptor(entityBean.getClass());
     BeanProperty idProperty = beanDesc.idProperty();
@@ -2205,14 +2220,15 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
     if (entityBean._ebean_getIntercept().isNew() && id != null) {
       // Primary Key is changeable only on new models - so skip check if we are not new
       SpiQuery<?> query = new DefaultOrmQuery<>(beanDesc, this, expressionFactory);
+      query.setUseQueryCache(useQueryCache);
       query.usingTransaction(transaction);
       query.setId(id);
-      if (findCount(query) > 0) {
+      if (exists(query)) {
         return Collections.singleton(idProperty);
       }
     }
     for (BeanProperty[] props : beanDesc.uniqueProps()) {
-      Set<Property> ret = checkUniqueness(entityBean, beanDesc, props, transaction);
+      Set<Property> ret = checkUniqueness(entityBean, beanDesc, props, transaction, useQueryCache, skipClean);
       if (ret != null) {
         return ret;
       }
@@ -2220,13 +2236,34 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
     return Collections.emptySet();
   }
 
+  /**
+   * Checks, if any property is dirty.
+   */
+  private boolean isAnyPropertyDirty(EntityBean entityBean, BeanProperty[] props) {
+    if (entityBean._ebean_getIntercept().isNew()) {
+      return true;
+    }
+    for (BeanProperty prop : props) {
+      if (entityBean._ebean_getIntercept().isDirtyProperty(prop.propertyIndex())) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   /**
    * Returns a set of properties if saving the bean will violate the unique constraints (defined by given properties).
    */
   @Nullable
-  private Set<Property> checkUniqueness(EntityBean entityBean, BeanDescriptor<?> beanDesc, BeanProperty[] props, @Nullable Transaction transaction) {
+  private Set<Property> checkUniqueness(EntityBean entityBean, BeanDescriptor<?> beanDesc, BeanProperty[] props, @Nullable Transaction transaction,
+                                        boolean useQueryCache, boolean skipClean) {
+    if (skipClean && !isAnyPropertyDirty(entityBean, props)) {
+      return null;
+    }
+
     BeanProperty idProperty = beanDesc.idProperty();
     SpiQuery<?> query = new DefaultOrmQuery<>(beanDesc, this, expressionFactory);
+    query.setUseQueryCache(useQueryCache);
     query.usingTransaction(transaction);
     ExpressionList<?> exprList = query.where();
     if (!entityBean._ebean_getIntercept().isNew()) {
@@ -2240,7 +2277,7 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
       }
       exprList.eq(prop.name(), value);
     }
-    if (findCount(query) > 0) {
+    if (exists(query)) {
       Set<Property> ret = new LinkedHashSet<>();
       Collections.addAll(ret, props);
       return ret;

ebean-core/src/main/java/io/ebeaninternal/server/core/DefaultSqlUpdate.java

@@ -2,6 +2,7 @@ package io.ebeaninternal.server.core;
 
 import io.ebean.DB;
 import io.ebean.SqlUpdate;
+import io.ebean.Transaction;
 import io.ebean.Update;
 import io.ebeaninternal.api.BindParams;
 import io.ebeaninternal.api.SpiEbeanServer;
@@ -140,7 +141,7 @@ public final class DefaultSqlUpdate implements Serializable, SpiSqlUpdate {
         server.executeBatch(this, transaction);
         return -1;
       }
-      return server.execute(this);
+      return server.execute(this, transaction);
     } else {
       // Hopefully this doesn't catch anyone out...
       return DB.getDefault().execute(this);
@@ -150,12 +151,18 @@ public final class DefaultSqlUpdate implements Serializable, SpiSqlUpdate {
   @Override
   public int executeNow() {
     if (server != null) {
-      return server.executeNow(this);
+      return server.executeNow(this, transaction);
     } else {
       throw new IllegalStateException("server is null?");
     }
   }
 
+  @Override
+  public SqlUpdate usingTransaction(Transaction transaction) {
+    this.transaction = (SpiTransaction) transaction;
+    return this;
+  }
+
   @Override
   public int[] executeBatch() {
     if (server == null) {

ebean-core/src/main/java/io/ebeaninternal/server/core/InternalConfiguration.java

@@ -2,6 +2,7 @@ package io.ebeaninternal.server.core;
 
 import io.avaje.json.stream.JsonStream;
 import io.ebean.DatabaseBuilder;
+import io.ebean.DtoMapperManager;
 import io.ebean.ExpressionFactory;
 import io.ebean.annotation.Platform;
 import io.ebean.cache.*;
@@ -76,6 +77,7 @@ public final class InternalConfiguration {
   private final DeployInherit deployInherit;
   private final TypeManager typeManager;
   private final DtoBeanManager dtoBeanManager;
+  private final DtoMapperManager dtoMapperManager;
   private final Clock clock;
   private final DataTimeZone dataTimeZone;
   private final Binder binder;
@@ -125,6 +127,7 @@ public final class InternalConfiguration {
 
     final InternalConfigXmlMap xmlMap = initExternalMapping();
     this.dtoBeanManager = new DtoBeanManager(typeManager, xmlMap.readDtoMapping());
+    this.dtoMapperManager = initDtoMapperManager();
     this.dataSourceSupplier = createDataSourceSupplier();
     this.beanDescriptorManager = new BeanDescriptorManager(this);
     Map<String, String> asOfTableMapping = beanDescriptorManager.deploy(xmlMap.xmlDeployment());
@@ -153,6 +156,17 @@ public final class InternalConfiguration {
     }
   }
 
+  /**
+   * Use an application-provided {@link DtoMapperManager} (registered via {@code
+   * config.putServiceObject(DtoMapperManager.class, ...)} before building the Database) if
+   * present, so the exact same instance (and hence the same underlying mapper instances) can be
+   * shared between {@code query.mapTo(...)} and application code, otherwise construct a default.
+   */
+  private DtoMapperManager initDtoMapperManager() {
+    DtoMapperManager manager = config.getServiceObject(DtoMapperManager.class);
+    return manager != null ? manager : new DtoMapperManager();
+  }
+
   private List<XmapEbean> readExternalMapping() {
     final XmapService xmapService = service(XmapService.class);
     if (xmapService == null) {
@@ -520,6 +534,10 @@ public final class InternalConfiguration {
     return dtoBeanManager;
   }
 
+  DtoMapperManager getDtoMapperManager() {
+    return dtoMapperManager;
+  }
+
   SpiLogManager getLogManager() {
     return logManager;
   }
@@ -589,7 +607,8 @@ public final class InternalConfiguration {
       return QueryPlanManager.NOOP;
     }
     long threshold = config.getQueryPlanThresholdMicros();
-    return new CQueryPlanManager(transactionManager, threshold, queryPlanLogger(databasePlatform.platform(), config), extraMetrics);
+    return new CQueryPlanManager(transactionManager, config.getCurrentTenantProvider(),
+      threshold, queryPlanLogger(databasePlatform.platform(), config), extraMetrics);
   }
 
   /**

ebean-core/src/main/java/io/ebeaninternal/server/core/OrmQueryEngine.java

@@ -49,6 +49,11 @@ public interface OrmQueryEngine {
    */
   <T> int findCount(OrmQueryRequest<T> request);
 
+  /**
+   * Execute the exists query using SELECT EXISTS(...).
+   */
+  <T> boolean findExists(OrmQueryRequest<T> request);
+
   /**
    * Execute the find id's query.
    */

ebean-core/src/main/java/io/ebeaninternal/server/core/OrmQueryRequest.java

@@ -127,6 +127,13 @@ public final class OrmQueryRequest<T> extends BeanRequest implements SpiOrmQuery
     }
   }
 
+  /**
+   * Return the secondary queries (fetchQuery and lazy joins) extracted from the query detail.
+   */
+  public SpiQuerySecondary secondaryQueries() {
+    return secondaryQueries;
+  }
+
   /**
    * For use with QueryIterator and secondary queries this returns the minimum
    * batch size that should be loaded before executing the secondary queries.
@@ -355,6 +362,11 @@ public final class OrmQueryRequest<T> extends BeanRequest implements SpiOrmQuery
     return queryEngine.findCount(this);
   }
 
+  @Override
+  public boolean findExists() {
+    return queryEngine.findExists(this);
+  }
+
   @Override
   public <A> List<A> findIds() {
     return queryEngine.findIds(this);

ebean-core/src/main/java/io/ebeaninternal/server/core/PersistRequestBean.java

@@ -56,6 +56,11 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
   private Object idValue;
   private boolean statelessUpdate;
   private boolean notifyCache;
+  /**
+   * Snapshot of origValues taken before intercept.setLoaded() clears them.
+   * Used so that cache update code can access old FK values after setLoaded().
+   */
+  private Object[] capturedOrigValues;
   /**
    * Flag used to detect when only many properties where updated via a cascade. Used to ensure
    * appropriate caches are updated in that case.
@@ -122,6 +127,18 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
    */
   private List<SaveMany> saveMany;
   private InsertOptions insertOptions;
+  /**
+   * Set true when an ON CONFLICT NOTHING insert is skipped (0 rows affected).
+   * Cascade to children must be suppressed to avoid FK violations.
+   */
+  private boolean insertConflictSkipped;
+  /**
+   * Set true once controller.preDelete() has been invoked so that it is
+   * only ever fired once (as it is fired early, prior to cascading the
+   * delete to children/many's rather than as part of executing the delete).
+   */
+  private boolean preDeleteCalled;
+  private boolean preDeleteResult = true;
 
   public PersistRequestBean(SpiEbeanServer server, T bean, Object parentBean, BeanManager<T> mgr, SpiTransaction t,
                             PersistExecute persistExecute, PersistRequest.Type type, int flags) {
@@ -710,7 +727,11 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
    * Return the original / old value for the given property.
    */
   public Object origValue(BeanProperty prop) {
-    return intercept.origValue(prop.propertyIndex());
+    int idx = prop.propertyIndex();
+    if (capturedOrigValues != null && idx < capturedOrigValues.length) {
+      return capturedOrigValues[idx];
+    }
+    return intercept.origValue(idx);
   }
 
   @Override
@@ -801,6 +822,9 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
         throw new OptimisticLockException("Data has changed. updated row count " + rowCount, null, bean);
       } else if (rowCount == 0 && type == Type.UPDATE) {
         throw new EntityNotFoundException("No rows updated");
+      } else if (rowCount == 0 && type == Type.INSERT && isConflictNothingInsert()) {
+        insertConflictSkipped = true;
+        return;
       }
     }
     switch (type) {
@@ -815,6 +839,14 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
     }
   }
 
+  private boolean isConflictNothingInsert() {
+    return insertOptions != null && insertOptions.key().charAt(0) == 'N';
+  }
+
+  public boolean isInsertConflictSkipped() {
+    return insertConflictSkipped;
+  }
+
   /**
    * Clear the bean from the PersistenceContext (L1 cache) for stateless updates.
    */
@@ -867,6 +899,15 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
     if (type == Type.UPDATE) {
       // get the dirty properties for notify cache & orphanRemoval of vanilla collection detection
       dirtyProperties = intercept.dirtyProperties();
+      // snapshot orig values before setLoaded() clears them - needed by cache FK-eviction logic
+      if (dirtyProperties != null && notifyCache) {
+        capturedOrigValues = new Object[dirtyProperties.length];
+        for (int i = 0; i < dirtyProperties.length; i++) {
+          if (dirtyProperties[i]) {
+            capturedOrigValues[i] = intercept.origValue(i);
+          }
+        }
+      }
     }
     if (isChangeLog) {
       changeLog();
@@ -903,6 +944,20 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
     }
   }
 
+  /**
+   * Ensure the preUpdate event fires (for case where only a ManyToMany collection has changed).
+   */
+  public void preManyToManyUpdate() {
+    if (controller != null && !dirty) {
+      // fire preUpdate notification when only ManyToMany intersection updated
+      controller.preUpdate(this);
+      pendingPostUpdateNotify = true;
+    }
+    if (!dirty) {
+      setNotifyCache();
+    }
+  }
+
   public boolean isNotifyCache() {
     return notifyCache;
   }
@@ -1228,14 +1283,29 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
   }
 
   private int executeDelete() {
-    setTenantId();
-    if (controller == null || controller.preDelete(this)) {
+    if (controllerPreDelete()) {
       return beanManager.getBeanPersister().delete(this);
     }
     // delete handled by the BeanController so return 0
     return 0;
   }
 
+  /**
+   * Invoke controller.preDelete() if not already invoked.
+   * <p>
+   * This is called prior to cascading the delete to children (assoc many's /
+   * many-to-many intersection rows) so that the persist controller can still
+   * see those collections/relationships as they were before the cascade delete.
+   */
+  public boolean controllerPreDelete() {
+    if (!preDeleteCalled) {
+      preDeleteCalled = true;
+      setTenantId();
+      preDeleteResult = controller == null || controller.preDelete(this);
+    }
+    return preDeleteResult;
+  }
+
   /**
    * Persist to the document store now (via buffer, not post commit).
    */
@@ -1415,7 +1485,12 @@ public final class PersistRequestBean<T> extends PersistRequest implements BeanP
   }
 
   public void setInsertOptions(InsertOptions insertOptions) {
-    this.insertOptions  = insertOptions;
+    this.insertOptions = insertOptions;
+    if (insertOptions != null && insertOptions.key().charAt(0) == 'N' && beanDescriptor.hasCascadeChildren()) {
+      // force immediate (non-batch) execution of this insert so we know whether it
+      // was actually inserted before attempting cascade saves on children.
+      skipBatchForTopLevel = true;
+    }
   }
 
   public InsertOptions insertOptions() {

ebean-core/src/main/java/io/ebeaninternal/server/core/SpiOrmQueryRequest.java

@@ -75,6 +75,11 @@ public interface SpiOrmQueryRequest<T> extends BeanQueryRequest<T>, DocQueryRequ
    */
   int findCount();
 
+  /**
+   * Execute the find exists query using select exists(...).
+   */
+  boolean findExists();
+
   /**
    * Execute the find ids query.
    */

ebean-core/src/main/java/io/ebeaninternal/server/deploy/AssocOneHelpEmbedded.java

@@ -10,8 +10,11 @@ import java.sql.SQLException;
  */
 final class AssocOneHelpEmbedded extends AssocOneHelp {
 
-  AssocOneHelpEmbedded(BeanPropertyAssocOne<?> property) {
+  private final boolean allowEmpty;
+
+  AssocOneHelpEmbedded(BeanPropertyAssocOne<?> property, boolean allowEmpty) {
     super(property);
+    this.allowEmpty = allowEmpty;
   }
 
   @Override
@@ -40,7 +43,7 @@ final class AssocOneHelpEmbedded extends AssocOneHelp {
         notNull = true;
       }
     }
-    if (notNull) {
+    if (notNull || allowEmpty) {
       return embeddedBean;
     } else {
       return null;
@@ -69,7 +72,7 @@ final class AssocOneHelpEmbedded extends AssocOneHelp {
         notNull = true;
       }
     }
-    return notNull ? embeddedBean : null;
+    return (notNull || allowEmpty) ? embeddedBean : null;
   }
 
   @Override

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanDescriptor.java

@@ -43,6 +43,8 @@ import io.ebeaninternal.server.deploy.meta.DeployBeanDescriptor;
 import io.ebeaninternal.server.deploy.meta.DeployBeanPropertyLists;
 import io.ebeaninternal.server.el.*;
 import io.ebeaninternal.server.persist.DeleteMode;
+import io.ebeaninternal.server.persist.MultiValueWrapper;
+import io.ebeaninternal.server.type.ScalarTypeArray;
 import io.ebeaninternal.server.query.*;
 import io.ebeaninternal.server.querydefn.DefaultOrmQuery;
 import io.ebeaninternal.server.querydefn.OrmQueryDetail;
@@ -320,7 +322,7 @@ public class BeanDescriptor<T> implements BeanType<T>, STreeType, SpiBeanType {
     this.idOnlyReference = isIdOnlyReference(propertiesBaseScalar);
     boolean noRelationships = propertiesOne.length + propertiesMany.length == 0;
     this.cacheSharableBeans = noRelationships && deploy.getCacheOptions().isReadOnly();
-    this.cacheHelp = new BeanDescriptorCacheHelp<>(this, owner.cacheManager(), deploy.getCacheOptions(), cacheSharableBeans, propertiesOneImported);
+    this.cacheHelp = BeanDescriptorCacheHelp.create(this, owner.cacheManager(), deploy.getCacheOptions(), cacheSharableBeans, propertiesOneImported);
     this.jsonHelp = initJsonHelp();
     this.draftHelp = new BeanDescriptorDraftHelp<>(this);
     this.docStoreAdapter = owner.createDocStoreBeanAdapter(this, deploy);
@@ -753,7 +755,16 @@ public class BeanDescriptor<T> implements BeanType<T>, STreeType, SpiBeanType {
   public void bindElementValue(SqlUpdate insert, Object value) {
     EntityBean bean = (EntityBean) value;
     for (BeanProperty property : propertiesBaseScalar) {
-      insert.setParameter(property.getValue(bean));
+      Object propertyValue = property.getValue(bean);
+      if (property.isArrayType() && propertyValue instanceof Collection) {
+        // Bind with the declared element type rather than relying on MultiValueWrapper's default
+        // constructor which infers the element type from the first value - this fails with a
+        // NoSuchElementException for an empty collection. See #2477.
+        Class<?> elementType = ((ScalarTypeArray) property.scalarType()).elementType();
+        insert.setParameter(new MultiValueWrapper((Collection<?>) propertyValue, elementType));
+      } else {
+        insert.setParameter(propertyValue);
+      }
     }
   }
 
@@ -2402,6 +2413,12 @@ public class BeanDescriptor<T> implements BeanType<T>, STreeType, SpiBeanType {
       if (assocProp == null) {
         return null;
       }
+      // this method is an entry-point, although it introduces recursive calls via
+      // buildElPropertyValue -> createElPropertyValue -> buildElGetValue (back to here)
+      // it seems we can initialize ElPropertyChainBuilder at this point and skip further checks.
+      if (chain == null) {
+        chain = new ElPropertyChainBuilder(propName);
+      }
       String remainder = propName.substring(basePos + 1);
       return assocProp.buildElPropertyValue(propName, remainder, chain, propertyDeploy);
     }
@@ -2413,9 +2430,7 @@ public class BeanDescriptor<T> implements BeanType<T>, STreeType, SpiBeanType {
     if (property == null) {
       throw new PersistenceException("No property found for [" + propName + "] in expression " + chain.expression());
     }
-    if (property.containsMany()) {
-      chain.setContainsMany();
-    }
+
     return chain.add(property).build();
   }
 
@@ -3337,6 +3352,15 @@ public class BeanDescriptor<T> implements BeanType<T>, STreeType, SpiBeanType {
     return propertiesManySave;
   }
 
+  /**
+   * Return true if this bean has cascade-save children (OneToMany or exported OneToOne)
+   * that hold a FK back to this bean. Used to decide whether an ON CONFLICT NOTHING
+   * insert must be executed immediately so the row-count is known before cascading.
+   */
+  public boolean hasCascadeChildren() {
+    return propertiesManySave.length > 0 || propertiesOneExportedSave.length > 0;
+  }
+
   /**
    * Assoc Many's with delete cascade.
    */

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorCacheHelp.java

@@ -27,7 +27,7 @@ import static java.lang.System.Logger.Level.*;
  *
  * @param <T> The entity bean type
  */
-final class BeanDescriptorCacheHelp<T> {
+abstract class BeanDescriptorCacheHelp<T> {
 
   private static final System.Logger log = CoreLog.internal;
 
@@ -36,7 +36,7 @@ final class BeanDescriptorCacheHelp<T> {
   private static final System.Logger manyLog = AppLog.getLogger("io.ebean.cache.COLL");
   private static final System.Logger natLog = AppLog.getLogger("io.ebean.cache.NATKEY");
 
-  private final BeanDescriptor<T> desc;
+  final BeanDescriptor<T> desc;
   private final SpiCacheManager cacheManager;
   private final CacheOptions cacheOptions;
   /**
@@ -44,13 +44,10 @@ final class BeanDescriptorCacheHelp<T> {
    */
   private final boolean cacheSharableBeans;
   private final boolean invalidateQueryCache;
-  private final Class<?> beanType;
+  final Class<?> beanType;
   private final String cacheName;
   private final BeanPropertyAssocOne<?>[] propertiesOneImported;
   private final String[] naturalKey;
-  private final ServerCache beanCache;
-  private final ServerCache naturalKeyCache;
-  private final ServerCache queryCache;
   private final boolean noCaching;
   private final SpiCacheControl cacheControl;
   private final SpiCacheRegion cacheRegion;
@@ -63,6 +60,21 @@ final class BeanDescriptorCacheHelp<T> {
    * Set to true if delete changes need to notify cache.
    */
   private boolean cacheNotifyOnDelete;
+  /**
+   * Set to true if this bean type has owning OneToOne properties pointing to cached targets.
+   * When true, all persist events must evict the target bean caches regardless of whether
+   * this bean type itself has a bean cache (bypasses the cacheRegion.isEnabled() gate).
+   */
+  private boolean cacheNotifyOneToOneOwner;
+
+  static <T> BeanDescriptorCacheHelp<T> create(BeanDescriptor<T> desc, SpiCacheManager cacheManager, CacheOptions cacheOptions,
+                                               boolean cacheSharableBeans, BeanPropertyAssocOne<?>[] propertiesOneImported) {
+    if ((cacheOptions.isEnableQueryCache() || cacheOptions.isEnableBeanCache()) && cacheManager.isTenantPartitionedCache()) {
+      return new BeanDescriptorCacheHelpPartitioned<>(desc, cacheManager, cacheOptions, cacheSharableBeans, propertiesOneImported);
+    } else {
+      return new BeanDescriptorCacheHelpFixed<>(desc, cacheManager, cacheOptions, cacheSharableBeans, propertiesOneImported);
+    }
+  }
 
   BeanDescriptorCacheHelp(BeanDescriptor<T> desc, SpiCacheManager cacheManager, CacheOptions cacheOptions,
                           boolean cacheSharableBeans, BeanPropertyAssocOne<?>[] propertiesOneImported) {
@@ -75,48 +87,54 @@ final class BeanDescriptorCacheHelp<T> {
     this.cacheSharableBeans = cacheSharableBeans;
     this.propertiesOneImported = propertiesOneImported;
     this.naturalKey = cacheOptions.getNaturalKey();
-    if (!cacheOptions.isEnableQueryCache()) {
-      this.queryCache = null;
-    } else {
-      this.queryCache = cacheManager.getQueryCache(beanType);
-    }
-
-    if (cacheOptions.isEnableBeanCache()) {
-      this.beanCache = cacheManager.getBeanCache(beanType);
-      if (cacheOptions.getNaturalKey() != null) {
-        this.naturalKeyCache = cacheManager.getNaturalKeyCache(beanType);
-      } else {
-        this.naturalKeyCache = null;
-      }
-    } else {
-      this.beanCache = null;
-      this.naturalKeyCache = null;
-    }
-    this.noCaching = (beanCache == null && queryCache == null);
+    this.noCaching = !cacheOptions.isEnableQueryCache() && !cacheOptions.isEnableBeanCache();
     if (noCaching) {
       this.cacheControl = DCacheControlNone.INSTANCE;
       this.cacheRegion = (invalidateQueryCache) ? cacheManager.getRegion(cacheOptions.getRegion()) : DCacheRegionNone.INSTANCE;
     } else {
       this.cacheRegion = cacheManager.getRegion(cacheOptions.getRegion());
-      this.cacheControl = new DCacheControl(cacheRegion, (beanCache != null), (naturalKeyCache != null), (queryCache != null));
+      this.cacheControl = new DCacheControl(cacheRegion,
+        cacheOptions.isEnableBeanCache(),
+        cacheOptions.isEnableBeanCache() && cacheOptions.getNaturalKey() != null,
+        cacheOptions.isEnableQueryCache());
     }
   }
 
+  abstract boolean hasBeanCache();
+
+  abstract boolean hasQueryCache();
+
+  abstract ServerCache queryCache();
+
+  abstract ServerCache naturalKeyCache();
+
+  abstract ServerCache beanCache();
+
   /**
    * Derive the cache notify flags.
    */
   void deriveNotifyFlags() {
-    cacheNotifyOnAll = (invalidateQueryCache || beanCache != null || queryCache != null);
+    cacheNotifyOnAll = (invalidateQueryCache || hasBeanCache() || hasQueryCache());
     cacheNotifyOnDelete = !cacheNotifyOnAll && isNotifyOnDeletes();
+    cacheNotifyOneToOneOwner = hasOwningOneToOneWithCachedTarget();
     if (log.isLoggable(DEBUG)) {
-      if (cacheNotifyOnAll || cacheNotifyOnDelete) {
-        String notifyMode = cacheNotifyOnAll ? "All" : "Delete";
+      if (cacheNotifyOnAll || cacheNotifyOnDelete || cacheNotifyOneToOneOwner) {
+        String notifyMode = cacheNotifyOnAll ? "All" : (cacheNotifyOnDelete ? "Delete" : "OneToOneOwner");
         log.log(DEBUG, "l2 caching on {0} - beanCaching:{1} queryCaching:{2} notifyMode:{3} ",
           desc.fullName(), isBeanCaching(), isQueryCaching(), notifyMode);
       }
     }
   }
 
+  private boolean hasOwningOneToOneWithCachedTarget() {
+    for (BeanPropertyAssocOne<?> imported : propertiesOneImported) {
+      if (imported.isCacheNotifyOwningOneToOne()) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   /**
    * Return true if there is an imported bi-directional relationship to a bea
    * that does have bean caching enabled.
@@ -137,6 +155,9 @@ final class BeanDescriptorCacheHelp<T> {
     if (hasImmutableCaches()) {
       return true;
     }
+    if (cacheNotifyOneToOneOwner) {
+      return true;
+    }
     return cacheRegion.isEnabled()
       && (cacheNotifyOnAll || cacheNotifyOnDelete && (type == PersistRequest.Type.DELETE || type == PersistRequest.Type.DELETE_PERMANENT));
   }
@@ -184,11 +205,11 @@ final class BeanDescriptorCacheHelp<T> {
    * Clear the query cache.
    */
   void queryCacheClear() {
-    if (queryCache != null) {
+    if (hasQueryCache()) {
       if (queryLog.isLoggable(DEBUG)) {
         queryLog.log(DEBUG, "   CLEAR {0}", cacheName);
       }
-      queryCache.clear();
+      queryCache().clear();
     }
   }
 
@@ -196,7 +217,7 @@ final class BeanDescriptorCacheHelp<T> {
    * Add query cache clear to the changeSet.
    */
   private void queryCacheClear(CacheChangeSet changeSet) {
-    if (queryCache != null) {
+    if (hasQueryCache()) {
       changeSet.addClearQuery(desc);
     }
   }
@@ -205,10 +226,10 @@ final class BeanDescriptorCacheHelp<T> {
    * Get a query result from the query cache.
    */
   Object queryCacheGet(Object id) {
-    if (queryCache == null) {
+    if (!hasQueryCache()) {
       throw new IllegalStateException("No query cache enabled on " + desc + ". Need explicit @Cache(enableQueryCache=true)");
     }
-    Object queryResult = queryCache.get(id);
+    Object queryResult = queryCache().get(id);
     if (queryLog.isLoggable(DEBUG)) {
       if (queryResult == null) {
         queryLog.log(DEBUG, "   GET {0}({1}) - cache miss", cacheName, id);
@@ -223,13 +244,13 @@ final class BeanDescriptorCacheHelp<T> {
    * Put a query result into the query cache.
    */
   void queryCachePut(Object id, QueryCacheEntry entry) {
-    if (queryCache == null) {
+    if (!hasQueryCache()) {
       throw new IllegalStateException("No query cache enabled on " + desc + ". Need explicit @Cache(enableQueryCache=true)");
     }
     if (queryLog.isLoggable(DEBUG)) {
       queryLog.log(DEBUG, "   PUT {0}({1})", cacheName, id);
     }
-    queryCache.put(id, entry);
+    queryCache().put(id, entry);
   }
 
   void manyPropRemove(String propertyName, String parentKey) {
@@ -300,7 +321,7 @@ final class BeanDescriptorCacheHelp<T> {
    */
   void manyPropPut(BeanPropertyAssocMany<?> many, Object details, String parentKey) {
     if (many.isElementCollection()) {
-      CachedBeanData data = (CachedBeanData) beanCache.get(parentKey);
+      CachedBeanData data = (CachedBeanData) beanCache().get(parentKey);
       if (data != null) {
         try {
           // add as JSON to bean cache
@@ -312,7 +333,7 @@ final class BeanDescriptorCacheHelp<T> {
           if (beanLog.isLoggable(DEBUG)) {
             beanLog.log(DEBUG, "   UPDATE {0}({1})  changes:{2}", cacheName, parentKey, changes);
           }
-          beanCache.put(parentKey, newData);
+          beanCache().put(parentKey, newData);
         } catch (IOException e) {
           log.log(ERROR, "Error updating L2 cache", e);
         }
@@ -351,14 +372,15 @@ final class BeanDescriptorCacheHelp<T> {
    * Hit the bean cache with the given ids returning the hits.
    */
   BeanCacheResult<T> cacheIdLookup(PersistenceContext context, boolean unmodifiable, Collection<?> ids) {
-    Set<Object> keys = new HashSet<>(ids.size());
-    for (Object id : ids) {
-      keys.add(desc.cacheKey(id));
-    }
     if (ids.isEmpty()) {
       return new BeanCacheResult<>();
     }
-    Map<Object, Object> beanDataMap = beanCache.getAll(keys);
+    // map cacheKey -> original id to support type coercion
+    Map<Object, Object> keyToOriginalId = new HashMap<>(ids.size());
+    for (Object id : ids) {
+      keyToOriginalId.put(desc.cacheKey(id), id);
+    }
+    Map<Object, Object> beanDataMap = beanCache().getAll(keyToOriginalId.keySet());
     if (beanLog.isLoggable(TRACE)) {
       beanLog.log(TRACE, "   MGET {0}({1}) - hits:{2}", cacheName, ids, beanDataMap.keySet());
     }
@@ -366,7 +388,8 @@ final class BeanDescriptorCacheHelp<T> {
     for (Map.Entry<Object, Object> entry : beanDataMap.entrySet()) {
       CachedBeanData cachedBeanData = (CachedBeanData) entry.getValue();
       T bean = convertToBean(entry.getKey(), unmodifiable, context, cachedBeanData);
-      result.add(bean, desc.id(bean));
+      Object originalId = keyToOriginalId.get(entry.getKey());
+      result.add(bean, originalId != null ? originalId : desc.id(bean));
     }
     return result;
   }
@@ -380,7 +403,7 @@ final class BeanDescriptorCacheHelp<T> {
     }
 
     // naturalKey -> Id map
-    Map<Object, Object> naturalKeyMap = naturalKeyCache.getAll(keys);
+    Map<Object, Object> naturalKeyMap = naturalKeyCache().getAll(keys);
     if (natLog.isLoggable(TRACE)) {
       natLog.log(TRACE, " MLOOKUP {0}({1}) - hits:{2}", cacheName, keys, naturalKeyMap);
     }
@@ -397,7 +420,7 @@ final class BeanDescriptorCacheHelp<T> {
     }
 
     Set<Object> ids = new HashSet<>(naturalKeyMap.values());
-    Map<Object, Object> beanDataMap = beanCache.getAll(ids);
+    Map<Object, Object> beanDataMap = beanCache().getAll(ids);
     if (beanLog.isLoggable(TRACE)) {
       beanLog.log(TRACE, "   MGET {0}({1}) - hits:{2}", cacheName, ids, beanDataMap.keySet());
     }
@@ -428,25 +451,15 @@ final class BeanDescriptorCacheHelp<T> {
     desc.contextPut(context, id, bean);
   }
 
-  /**
-   * Return the beanCache creating it if necessary.
-   */
-  private ServerCache getBeanCache() {
-    if (beanCache == null) {
-      throw new IllegalStateException("No bean cache enabled for " + desc + ". Add the @Cache annotation.");
-    }
-    return beanCache;
-  }
-
   /**
    * Clear the bean cache.
    */
   void beanCacheClear() {
-    if (beanCache != null) {
+    if (hasBeanCache()) {
       if (beanLog.isLoggable(DEBUG)) {
         beanLog.log(DEBUG, "   CLEAR {0}", cacheName);
       }
-      beanCache.clear();
+      beanCache().clear();
     }
   }
 
@@ -516,13 +529,13 @@ final class BeanDescriptorCacheHelp<T> {
     if (beanLog.isLoggable(DEBUG)) {
       beanLog.log(DEBUG, "   MPUT {0}({1})", cacheName, map.keySet());
     }
-    getBeanCache().putAll(map);
+    beanCache().putAll(map);
 
     if (natKeys != null && !natKeys.isEmpty()) {
       if (natLog.isLoggable(DEBUG)) {
         natLog.log(DEBUG, " MPUT {0}({1}, {2})", cacheName, Arrays.toString(naturalKey), natKeys.keySet());
       }
-      naturalKeyCache.putAll(natKeys);
+      naturalKeyCache().putAll(natKeys);
     }
   }
 
@@ -535,14 +548,14 @@ final class BeanDescriptorCacheHelp<T> {
     if (beanLog.isLoggable(DEBUG)) {
       beanLog.log(DEBUG, "   PUT {0}({1}) data:{2}", cacheName, key, beanData);
     }
-    getBeanCache().put(key, beanData);
+    beanCache().put(key, beanData);
     if (naturalKey != null) {
       String naturalKey = calculateNaturalKey(beanData);
       if (naturalKey != null) {
         if (natLog.isLoggable(DEBUG)) {
           natLog.log(DEBUG, " PUT {0}({1}, {2})", cacheName, naturalKey, key);
         }
-        naturalKeyCache.put(naturalKey, key);
+        naturalKeyCache().put(naturalKey, key);
       }
     }
   }
@@ -564,7 +577,7 @@ final class BeanDescriptorCacheHelp<T> {
   }
 
   CachedBeanData beanCacheGetData(String key) {
-    return (CachedBeanData) getBeanCache().get(key);
+    return (CachedBeanData) beanCache().get(key);
   }
 
   T beanCacheGet(String key, boolean unmodifiable, PersistenceContext context) {
@@ -579,7 +592,7 @@ final class BeanDescriptorCacheHelp<T> {
    * Return a bean from the bean cache.
    */
   private T beanCacheGetInternal(String key, boolean unmodifiable, PersistenceContext context) {
-    CachedBeanData data = (CachedBeanData) getBeanCache().get(key);
+    CachedBeanData data = (CachedBeanData) beanCache().get(key);
     if (data == null) {
       if (beanLog.isLoggable(TRACE)) {
         beanLog.log(TRACE, "   GET {0}({1}) - cache miss", cacheName, key);
@@ -684,11 +697,11 @@ final class BeanDescriptorCacheHelp<T> {
    * Remove a bean from the cache given its Id.
    */
   void beanCacheApplyInvalidate(Collection<String> keys) {
-    if (beanCache != null) {
+    if (hasBeanCache()) {
       if (beanLog.isLoggable(DEBUG)) {
         beanLog.log(DEBUG, "   MREMOVE {0}({1})", cacheName, keys);
       }
-      beanCache.removeAll(new HashSet<>(keys));
+      beanCache().removeAll(new HashSet<>(keys));
     }
     for (BeanPropertyAssocOne<?> imported : propertiesOneImported) {
       imported.cacheClear();
@@ -704,7 +717,7 @@ final class BeanDescriptorCacheHelp<T> {
       ebis.put(desc.cacheKeyForBean(ebi.owner()), ebi);
     }
 
-    Map<Object, Object> hits = getBeanCache().getAll(ebis.keySet());
+    Map<Object, Object> hits = beanCache().getAll(ebis.keySet());
     if (beanLog.isLoggable(TRACE)) {
       beanLog.log(TRACE, "   MLOAD {0}({1}) - got hits ({2})", cacheName, ebis.keySet(), hits.size());
     }
@@ -737,7 +750,7 @@ final class BeanDescriptorCacheHelp<T> {
    * Returns true if it managed to populate/load the single bean from the cache.
    */
   boolean beanCacheLoad(EntityBean bean, EntityBeanIntercept ebi, String key, PersistenceContext context) {
-    CachedBeanData cacheData = (CachedBeanData) getBeanCache().get(key);
+    CachedBeanData cacheData = (CachedBeanData) beanCache().get(key);
     if (cacheData == null) {
       if (beanLog.isLoggable(TRACE)) {
         beanLog.log(TRACE, "   LOAD {0}({1}) - cache miss", cacheName, key);
@@ -759,7 +772,7 @@ final class BeanDescriptorCacheHelp<T> {
   }
 
   void cacheUpdateQuery(boolean update, SpiTransaction transaction) {
-    if (invalidateQueryCache || cacheNotifyOnAll || (!update && cacheNotifyOnDelete)) {
+    if (invalidateQueryCache || cacheNotifyOnAll || cacheNotifyOneToOneOwner || (!update && cacheNotifyOnDelete)) {
       transaction.event().add(desc.baseTable(), false, update, !update);
     }
   }
@@ -775,10 +788,11 @@ final class BeanDescriptorCacheHelp<T> {
       changeSet.addInvalidate(desc);
     } else {
       queryCacheClear(changeSet);
-      if (beanCache != null) {
+      if (hasBeanCache()) {
         changeSet.addBeanRemoveMany(desc, ids);
       }
       cacheDeleteImported(true, null, changeSet);
+      cacheClearImportedOneToOne(changeSet);
     }
   }
 
@@ -793,10 +807,11 @@ final class BeanDescriptorCacheHelp<T> {
       changeSet.addInvalidate(desc);
     } else {
       queryCacheClear(changeSet);
-      if (beanCache != null) {
+      if (hasBeanCache()) {
         changeSet.addBeanRemove(desc, id);
       }
       cacheDeleteImported(true, deleteRequest.entityBean(), changeSet);
+      cacheDeleteImportedOneToOne(deleteRequest.entityBean(), changeSet);
     }
   }
 
@@ -809,6 +824,7 @@ final class BeanDescriptorCacheHelp<T> {
     } else {
       queryCacheClear(changeSet);
       cacheDeleteImported(false, insertRequest.entityBean(), changeSet);
+      cacheDeleteImportedOneToOne(insertRequest.entityBean(), changeSet);
       changeSet.addBeanInsert(desc.baseTable());
     }
   }
@@ -819,6 +835,42 @@ final class BeanDescriptorCacheHelp<T> {
     }
   }
 
+  /**
+   * Evict the target bean cache for each owning OneToOne property on insert or delete.
+   */
+  private void cacheDeleteImportedOneToOne(EntityBean entityBean, CacheChangeSet changeSet) {
+    for (BeanPropertyAssocOne<?> imported : propertiesOneImported) {
+      imported.cacheDeleteOneToOneOwned(entityBean, changeSet);
+    }
+  }
+
+  /**
+   * Clear the target bean cache for each owning OneToOne property on bulk delete-by-ids.
+   */
+  private void cacheClearImportedOneToOne(CacheChangeSet changeSet) {
+    for (BeanPropertyAssocOne<?> imported : propertiesOneImported) {
+      imported.cacheClearOneToOneOwned(changeSet);
+    }
+  }
+
+  /**
+   * Evict inverse caches for any imported FK properties whose value changed in this update.
+   * Handles collection-ids caches (ManyToOne FK reassignment) and bean caches (owning OneToOne FK change).
+   */
+  private void cacheUpdateImportedFKs(PersistRequestBean<T> updateRequest, CacheChangeSet changeSet) {
+    boolean[] dirty = updateRequest.dirtyProperties();
+    if (dirty == null) {
+      return;
+    }
+    EntityBean entityBean = updateRequest.entityBean();
+    for (BeanPropertyAssocOne<?> imported : propertiesOneImported) {
+      int propIdx = imported.propertyIndex();
+      if (propIdx < dirty.length && dirty[propIdx]) {
+        imported.cacheUpdateFKchange(entityBean, updateRequest.origValue(imported), changeSet);
+      }
+    }
+  }
+
   /**
    * Add appropriate changes to support update.
    */
@@ -831,7 +883,8 @@ final class BeanDescriptorCacheHelp<T> {
 
     } else {
       queryCacheClear(changeSet);
-      if (beanCache == null) {
+      cacheUpdateImportedFKs(updateRequest, changeSet);
+      if (!hasBeanCache()) {
         // query caching only
         return;
       }
@@ -861,15 +914,17 @@ final class BeanDescriptorCacheHelp<T> {
       changeSet.addInvalidate(desc);
       return;
     }
-    if (noCaching) {
+    if (noCaching && !cacheNotifyOneToOneOwner) {
       return;
     }
-    changeSet.addClearQuery(desc);
-    // inserts don't invalidate the bean cache
-    if (tableIUD.isUpdateOrDelete()) {
-      changeSet.addClearBean(desc);
+    if (!noCaching) {
+      changeSet.addClearQuery(desc);
+      // inserts don't invalidate the bean cache
+      if (tableIUD.isUpdateOrDelete()) {
+        changeSet.addClearBean(desc);
+      }
     }
-    // any change invalidates the collection IDs cache
+    // any change invalidates the collection IDs cache and owning OneToOne target bean caches
     for (BeanPropertyAssocOne<?> imported : propertiesOneImported) {
       imported.cacheClear(changeSet);
     }
@@ -877,7 +932,7 @@ final class BeanDescriptorCacheHelp<T> {
 
   void cacheNaturalKeyPut(String key, String newKey) {
     if (newKey != null) {
-      naturalKeyCache.put(newKey, key);
+      naturalKeyCache().put(newKey, key);
     }
   }
 
@@ -885,7 +940,7 @@ final class BeanDescriptorCacheHelp<T> {
    * Apply changes to the bean cache entry.
    */
   void cacheBeanUpdate(String key, Map<String, Object> changes, boolean updateNaturalKey, long version) {
-    ServerCache cache = getBeanCache();
+    ServerCache cache = beanCache();
     CachedBeanData existingData = (CachedBeanData) cache.get(key);
     if (existingData != null) {
       long currentVersion = existingData.getVersion();
@@ -910,7 +965,7 @@ final class BeanDescriptorCacheHelp<T> {
           if (natLog.isLoggable(DEBUG)) {
             natLog.log(DEBUG, ".. update {0} REMOVE({1}) - old key for ({2})", cacheName, oldKey, key);
           }
-          naturalKeyCache.remove(oldKey);
+          naturalKeyCache().remove(oldKey);
         }
       }
     }

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorCacheHelpFixed.java

@@ -0,0 +1,63 @@
+package io.ebeaninternal.server.deploy;
+
+import io.ebean.cache.ServerCache;
+import io.ebeaninternal.server.cache.SpiCacheManager;
+import io.ebeaninternal.server.core.CacheOptions;
+
+/**
+ * BeanDescriptorCacheHelp implementation for non-tenant-partitioned (fixed) caches.
+ * Cache instances are obtained once at construction time and reused for all requests.
+ *
+ * @param <T> The entity bean type
+ */
+final class BeanDescriptorCacheHelpFixed<T> extends BeanDescriptorCacheHelp<T> {
+
+  private final ServerCache beanCache;
+  private final ServerCache naturalKeyCache;
+  private final ServerCache queryCache;
+
+  BeanDescriptorCacheHelpFixed(BeanDescriptor<T> desc, SpiCacheManager cacheManager, CacheOptions cacheOptions,
+                               boolean cacheSharableBeans, BeanPropertyAssocOne<?>[] propertiesOneImported) {
+    super(desc, cacheManager, cacheOptions, cacheSharableBeans, propertiesOneImported);
+    if (!cacheOptions.isEnableQueryCache()) {
+      this.queryCache = null;
+    } else {
+      this.queryCache = cacheManager.getQueryCache(beanType);
+    }
+    if (cacheOptions.isEnableBeanCache()) {
+      this.beanCache = cacheManager.getBeanCache(beanType);
+      this.naturalKeyCache = (cacheOptions.getNaturalKey() != null) ? cacheManager.getNaturalKeyCache(beanType) : null;
+    } else {
+      this.beanCache = null;
+      this.naturalKeyCache = null;
+    }
+  }
+
+  @Override
+  boolean hasBeanCache() {
+    return beanCache != null;
+  }
+
+  @Override
+  boolean hasQueryCache() {
+    return queryCache != null;
+  }
+
+  @Override
+  ServerCache queryCache() {
+    return queryCache;
+  }
+
+  @Override
+  ServerCache naturalKeyCache() {
+    return naturalKeyCache;
+  }
+
+  @Override
+  ServerCache beanCache() {
+    if (beanCache == null) {
+      throw new IllegalStateException("No bean cache enabled for " + desc + ". Add the @Cache annotation.");
+    }
+    return beanCache;
+  }
+}

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorCacheHelpPartitioned.java

@@ -0,0 +1,62 @@
+package io.ebeaninternal.server.deploy;
+
+import io.ebean.cache.ServerCache;
+import io.ebeaninternal.server.cache.SpiCacheManager;
+import io.ebeaninternal.server.core.CacheOptions;
+
+import java.util.function.Supplier;
+
+/**
+ * BeanDescriptorCacheHelp implementation for tenant-partitioned caches.
+ * Cache instances are looked up on every access via the cacheManager (which resolves the
+ * correct tenant-namespaced cache using the current tenant id from the tenant provider).
+ *
+ * @param <T> The entity bean type
+ */
+final class BeanDescriptorCacheHelpPartitioned<T> extends BeanDescriptorCacheHelp<T> {
+
+  private final Supplier<ServerCache> beanCacheSupplier;
+  private final Supplier<ServerCache> naturalKeyCacheSupplier;
+  private final Supplier<ServerCache> queryCacheSupplier;
+
+  BeanDescriptorCacheHelpPartitioned(BeanDescriptor<T> desc, SpiCacheManager cacheManager, CacheOptions cacheOptions,
+                                     boolean cacheSharableBeans, BeanPropertyAssocOne<?>[] propertiesOneImported) {
+    super(desc, cacheManager, cacheOptions, cacheSharableBeans, propertiesOneImported);
+    this.queryCacheSupplier = cacheOptions.isEnableQueryCache() ? () -> cacheManager.getQueryCache(beanType) : null;
+    if (cacheOptions.isEnableBeanCache()) {
+      this.beanCacheSupplier = () -> cacheManager.getBeanCache(beanType);
+      this.naturalKeyCacheSupplier = (cacheOptions.getNaturalKey() != null) ? () -> cacheManager.getNaturalKeyCache(beanType) : null;
+    } else {
+      this.beanCacheSupplier = null;
+      this.naturalKeyCacheSupplier = null;
+    }
+  }
+
+  @Override
+  boolean hasBeanCache() {
+    return beanCacheSupplier != null;
+  }
+
+  @Override
+  boolean hasQueryCache() {
+    return queryCacheSupplier != null;
+  }
+
+  @Override
+  ServerCache queryCache() {
+    return queryCacheSupplier.get();
+  }
+
+  @Override
+  ServerCache naturalKeyCache() {
+    return naturalKeyCacheSupplier.get();
+  }
+
+  @Override
+  ServerCache beanCache() {
+    if (beanCacheSupplier == null) {
+      throw new IllegalStateException("No bean cache enabled for " + desc + ". Add the @Cache annotation.");
+    }
+    return beanCacheSupplier.get();
+  }
+}

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorManager.java

@@ -907,8 +907,18 @@ public final class BeanDescriptorManager implements BeanDescriptorMap, SpiBeanTy
   }
 
   private void makeOrderColumn(DeployBeanPropertyAssocMany<?> oneToMany) {
-    DeployBeanDescriptor<?> targetDesc = targetDescriptor(oneToMany);
-    DeployOrderColumn orderColumn = oneToMany.getOrderColumn();
+    makeOrderColumn(oneToMany, targetDescriptor(oneToMany));
+  }
+
+  /**
+   * Create and assign the synthetic order column property onto the given target descriptor.
+   * <p>
+   * Used for both {@code @OneToMany} (targetDesc looked up via the target entity type) and
+   * {@code @ElementCollection} (targetDesc is the synthetic element descriptor which is not
+   * registered in {@code deployInfoMap} and so must be passed in directly).
+   */
+  public void makeOrderColumn(DeployBeanPropertyAssocMany<?> many, DeployBeanDescriptor<?> targetDesc) {
+    DeployOrderColumn orderColumn = many.getOrderColumn();
     final ScalarType<?> scalarType = typeManager.type(Integer.class);
     DeployBeanProperty orderProperty = new DeployBeanProperty(targetDesc, Integer.class, scalarType, null);
     orderProperty.setName(DeployOrderColumn.LOGICAL_NAME);

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanProperty.java

@@ -671,6 +671,35 @@ public class BeanProperty implements ElPropertyValue, Property, STreeProperty {
     setValue(entityBean, tenantId);
   }
 
+  /**
+   * By default, getIntercept and setIntercept will check if the passed bean is an instance of the descriptor type.
+   * <p>
+   * If the property is not part of the type hierarchy (i.e. is not this property from this descriptor) an
+   * IllegalArgumentException is thrown.
+   * <p>
+   * If inheritance is involved, this method returns false instead of throwing an exception, if the property might
+   * exist on one of the sibling child beans. This is necessary for getIntercept, as it returns <code>null</code>
+   * in this case.
+   *
+   * @return true if the property can be accessed on the given bean, false if it should be treated as unloaded.
+   */
+  private boolean checkPropertyAccess(EntityBean bean) {
+    if (bean == null || descriptor.type().isInstance(bean)) { // null = fall through - NPE is caught later.
+      return true;
+    }
+    InheritInfo inheritInfo = descriptor.inheritInfo();
+    if (inheritInfo == null || inheritInfo.isRoot() || !inheritInfo.getRoot().getType().isInstance(bean)) {
+      throw new IllegalArgumentException(propertyIncompatibleMsg(bean));
+    } else {
+      return false;
+    }
+  }
+
+  private String propertyIncompatibleMsg(EntityBean bean) {
+    String beanType = bean == null ? "null" : bean.getClass().getName();
+    return "Property " + name + " on [" + descriptor + "] is incompatible with type[" + beanType + "]";
+  }
+
   /**
    * Set the value of the property without interception or
    * PropertyChangeSupport.
@@ -687,6 +716,9 @@ public class BeanProperty implements ElPropertyValue, Property, STreeProperty {
    * Set the value of the property.
    */
   public void setValueIntercept(EntityBean bean, Object value) {
+    if (!checkPropertyAccess(bean)) {
+      throw new IllegalArgumentException(propertyIncompatibleMsg(bean));
+    }
     try {
       setter.setIntercept(bean, value);
     } catch (Exception ex) {
@@ -798,6 +830,9 @@ public class BeanProperty implements ElPropertyValue, Property, STreeProperty {
   }
 
   public Object getValueIntercept(EntityBean bean) {
+    if (!checkPropertyAccess(bean)) {
+      return null;
+    }
     try {
       return getter.getIntercept(bean);
     } catch (Exception ex) {

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanPropertyAssoc.java

@@ -161,13 +161,7 @@ public abstract class BeanPropertyAssoc<T> extends BeanProperty implements STree
   ElPropertyValue createElPropertyValue(String propName, String remainder, ElPropertyChainBuilder chain, boolean propertyDeploy) {
     // associated or embedded bean
     BeanDescriptor<?> embDesc = targetDescriptor();
-    if (chain == null) {
-      chain = new ElPropertyChainBuilder(isEmbedded(), propName);
-    }
     chain.add(this);
-    if (containsMany()) {
-      chain.setContainsMany();
-    }
     return embDesc.buildElGetValue(remainder, chain, propertyDeploy);
   }
 
@@ -217,6 +211,10 @@ public abstract class BeanPropertyAssoc<T> extends BeanProperty implements STree
    * Return the BeanDescriptor of the target.
    */
   public BeanDescriptor<T> targetDescriptor() {
+    if (targetDescriptor == null) {
+      // lazily resolve for association properties inside an @Embeddable used as override copy
+      targetDescriptor = descriptor.descriptor(targetType);
+    }
     return targetDescriptor;
   }
 

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanPropertyAssocMany.java

@@ -57,6 +57,12 @@ public class BeanPropertyAssocMany<T> extends BeanPropertyAssoc<T> implements ST
    * Flag to indicate that the target has a order column to auto populate.
    */
   private final boolean hasOrderColumn;
+  /**
+   * For ManyToMany, the db column name of the order column stored on the intersection
+   * table (null for OneToMany/ElementCollection which use a target descriptor property instead).
+   */
+  private final String intersectionOrderColumn;
+  private final boolean intersectionOrderColumnNullable;
   /**
    * Flag to indicate manyToMany relationship.
    */
@@ -95,6 +101,8 @@ public class BeanPropertyAssocMany<T> extends BeanPropertyAssoc<T> implements ST
     this.o2mJoinTable = deploy.isO2mJoinTable();
     this.hasOrderColumn = deploy.hasOrderColumn();
     this.manyToMany = deploy.isManyToMany();
+    this.intersectionOrderColumn = (manyToMany && hasOrderColumn) ? deploy.getOrderColumn().getName() : null;
+    this.intersectionOrderColumnNullable = (manyToMany && hasOrderColumn) && deploy.getOrderColumn().isNullable();
     this.elementCollection = deploy.isElementCollection();
     this.elementDescriptor = deploy.getElementDescriptor();
     this.manyType = deploy.getManyType();
@@ -154,6 +162,9 @@ public class BeanPropertyAssocMany<T> extends BeanPropertyAssoc<T> implements ST
         embeddedExportedProperties = exportedProperties[0].isEmbedded();
         if (fetchOrderBy != null) {
           lazyFetchOrderBy = sqlHelp.lazyFetchOrderBy(fetchOrderBy);
+        } else if (intersectionOrderColumn != null) {
+          // ManyToMany @OrderColumn - the intersection table is always aliased "int_"
+          lazyFetchOrderBy = sqlHelp.lazyFetchOrderBy("int_." + intersectionOrderColumn);
         }
       }
     }
@@ -511,6 +522,29 @@ public class BeanPropertyAssocMany<T> extends BeanPropertyAssoc<T> implements ST
     return hasOrderColumn;
   }
 
+  /**
+   * Return true if this is a ManyToMany with an order column stored on the intersection table.
+   */
+  @Override
+  public boolean hasIntersectionOrderColumn() {
+    return intersectionOrderColumn != null;
+  }
+
+  /**
+   * Return the db column name of the ManyToMany intersection table order column (or null).
+   */
+  @Override
+  public String intersectionOrderColumn() {
+    return intersectionOrderColumn;
+  }
+
+  /**
+   * Return true if the intersection table order column is nullable.
+   */
+  public boolean isIntersectionOrderColumnNullable() {
+    return intersectionOrderColumnNullable;
+  }
+
   public boolean isOrphanRemoval() {
     return orphanRemoval;
   }

ebean-core/src/main/java/io/ebeaninternal/server/deploy/BeanPropertyAssocOne.java

@@ -45,6 +45,7 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
   private final boolean orphanRemoval;
   private final boolean primaryKeyExport;
   private final boolean primaryKeyJoin;
+  private final boolean embeddedAllowEmpty;
 
   private AssocOneHelp localHelp;
   final BeanProperty[] embeddedProps;
@@ -54,6 +55,7 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
   private String deleteByParentIdInSql;
   private BeanPropertyAssocMany<?> relationshipProperty;
   private boolean cacheNotifyRelationship;
+  private boolean cacheNotifyOwningOneToOne;
 
   /**
    * Create based on deploy information of an EmbeddedId.
@@ -73,6 +75,7 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
     oneToOne = deploy.isOneToOne();
     oneToOneExported = deploy.isOneToOneExported();
     orphanRemoval = deploy.isOrphanRemoval();
+    embeddedAllowEmpty = deploy.isEmbeddedAllowEmpty();
     if (embedded) {
       // Overriding of the columns and use table alias of owning BeanDescriptor
       BeanEmbeddedMeta overrideMeta = BeanEmbeddedMetaFactory.create(owner, deploy);
@@ -99,6 +102,7 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
     oneToOne = source.oneToOne;
     oneToOneExported = source.oneToOneExported;
     orphanRemoval = source.orphanRemoval;
+    embeddedAllowEmpty = source.embeddedAllowEmpty;
     embeddedProps = null;
     embeddedPropsMap = null;
   }
@@ -143,6 +147,7 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
    */
   void initialisePostTarget() {
     this.cacheNotifyRelationship = isCacheNotifyRelationship();
+    this.cacheNotifyOwningOneToOne = oneToOne && !oneToOneExported && targetDescriptor.isBeanCaching();
   }
 
   /**
@@ -165,18 +170,31 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
   }
 
   /**
-   * Clear the L2 relationship cache for this property.
+   * Return true if this owning OneToOne property requires target bean cache eviction on change.
+   */
+  boolean isCacheNotifyOwningOneToOne() {
+    return cacheNotifyOwningOneToOne;
+  }
+
+  /**
+   * Clear the L2 relationship cache for this property (used from beanCacheApplyInvalidate).
    */
   void cacheClear() {
     if (cacheNotifyRelationship) {
       targetDescriptor.cacheManyPropClear(relationshipProperty.name());
     }
+    if (cacheNotifyOwningOneToOne) {
+      targetDescriptor.clearBeanCache();
+    }
   }
 
   void cacheClear(CacheChangeSet changeSet) {
     if (cacheNotifyRelationship) {
       changeSet.addManyClear(targetDescriptor, relationshipProperty.name());
     }
+    if (cacheNotifyOwningOneToOne) {
+      changeSet.addClearBean(targetDescriptor);
+    }
   }
 
   /**
@@ -199,6 +217,66 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
     }
   }
 
+  /**
+   * Evict the target's bean cache entry when this owning OneToOne bean is inserted or deleted.
+   */
+  void cacheDeleteOneToOneOwned(EntityBean bean, CacheChangeSet changeSet) {
+    if (cacheNotifyOwningOneToOne) {
+      Object assocBean = getValue(bean);
+      if (assocBean != null) {
+        Object targetId = targetDescriptor.id(assocBean);
+        if (targetId != null) {
+          changeSet.addBeanRemove(targetDescriptor, targetId);
+        }
+      }
+    }
+  }
+
+  /**
+   * Clear the target's entire bean cache when owning OneToOne beans are deleted by IDs.
+   */
+  void cacheClearOneToOneOwned(CacheChangeSet changeSet) {
+    if (cacheNotifyOwningOneToOne) {
+      changeSet.addClearBean(targetDescriptor);
+    }
+  }
+
+  /**
+   * Evict the inverse caches for BOTH old and new targets when the FK changes on update.
+   * Handles collection-ids caches (ManyToOne) and bean caches (owning OneToOne).
+   */
+  void cacheUpdateFKchange(EntityBean bean, Object origAssocBean, CacheChangeSet changeSet) {
+    Object newAssocBean = getValue(bean);
+    if (cacheNotifyRelationship) {
+      if (origAssocBean != null) {
+        Object oldId = targetDescriptor.id(origAssocBean);
+        if (oldId != null) {
+          changeSet.addManyRemove(targetDescriptor, relationshipProperty.name(), targetDescriptor.cacheKey(oldId));
+        }
+      }
+      if (newAssocBean != null) {
+        Object newId = targetDescriptor.id(newAssocBean);
+        if (newId != null) {
+          changeSet.addManyRemove(targetDescriptor, relationshipProperty.name(), targetDescriptor.cacheKey(newId));
+        }
+      }
+    }
+    if (cacheNotifyOwningOneToOne) {
+      if (origAssocBean != null) {
+        Object oldId = targetDescriptor.id(origAssocBean);
+        if (oldId != null) {
+          changeSet.addBeanRemove(targetDescriptor, oldId);
+        }
+      }
+      if (newAssocBean != null) {
+        Object newId = targetDescriptor.id(newAssocBean);
+        if (newId != null) {
+          changeSet.addBeanRemove(targetDescriptor, newId);
+        }
+      }
+    }
+  }
+
   @Override
   Object naturalKeyVal(Map<String, Object> values) {
     EntityBean bean = (EntityBean) values.get(name);
@@ -211,15 +289,31 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
   @Override
   public ElPropertyValue buildElPropertyValue(String propName, String remainder, ElPropertyChainBuilder chain, boolean propertyDeploy) {
     if (embedded) {
-      BeanProperty embProp = embeddedPropsMap.get(remainder);
+      String embName = remainder;
+      String embRemainder = null;
+      int basePos = remainder.indexOf('.');
+      if (basePos > -1) {
+        embName = remainder.substring(0, basePos);
+        embRemainder = remainder.substring(basePos + 1);
+      }
+      BeanProperty embProp = embeddedPropsMap.get(embName);
+
       if (embProp == null) {
-        String msg = "Embedded Property " + remainder + " not found in " + fullName();
+        String msg = "Embedded Property " + embName + " not found in " + fullName();
         throw new PersistenceException(msg);
       }
-      if (chain == null) {
-        chain = new ElPropertyChainBuilder(true, propName);
-      }
       chain.add(this);
+      if (embRemainder != null) {
+        if (embProp instanceof BeanPropertyAssocOne) {
+          // @ManyToOne using the overridden property, e.g. "ma_country_code" instead of "country_code")
+          return embProp.buildElPropertyValue(propName, embRemainder, chain, propertyDeploy);
+        }
+        // scalar (or non-navigable) leaf with a further path segment - invalid path
+        String msg = "Embedded Property " + embName + "." + embRemainder + " not found in " + fullName();
+        throw new PersistenceException(msg);
+      }
+      // direct scalar/assoc access within embedded — mark as embedded so the prefix
+      // strips the embedded segment (keeps parent table alias, not the embedded segment)
       chain.setEmbedded(true);
       return chain.add(embProp).build();
     }
@@ -749,7 +843,7 @@ public class BeanPropertyAssocOne<T> extends BeanPropertyAssoc<T> implements STr
 
   private AssocOneHelp createHelp(boolean embedded, boolean oneToOneExported, String embeddedPrefix) {
     if (embedded) {
-      return new AssocOneHelpEmbedded(this);
+      return new AssocOneHelpEmbedded(this, embeddedAllowEmpty);
     } else if (oneToOneExported) {
       return new AssocOneHelpRefExported(this);
     } else {

ebean-core/src/main/java/io/ebeaninternal/server/deploy/DbSqlContext.java

@@ -181,4 +181,11 @@ public interface DbSqlContext {
    * Include the filter many predicates if specified into the JOIN clause.
    */
   void includeFilterMany();
+
+  /**
+   * Return true if the given fetch path (relative to the query root) is the exact join clause
+   * that the pending filterMany predicate must be attached to - i.e. the deepest path the
+   * filterMany expression itself references.
+   */
+  boolean isFilterManyAttachPoint(String prefix);
 }

ebean-core/src/main/java/io/ebeaninternal/server/deploy/id/IdBinderSimple.java

@@ -234,6 +234,10 @@ public final class IdBinderSimple implements IdBinder {
   @Override
   public Object convertId(Object idValue) {
     if (!idValue.getClass().equals(expectedType)) {
+      if (idValue instanceof String) {
+        // for cacheKey() formatted values
+        return scalarType.parse((String) idValue);
+      }
       return scalarType.toBeanType(idValue);
     }
     return idValue;

ebean-core/src/main/java/io/ebeaninternal/server/deploy/meta/DeployBeanPropertyAssocOne.java

@@ -13,6 +13,7 @@ public final class DeployBeanPropertyAssocOne<T> extends DeployBeanPropertyAssoc
   private boolean oneToOneExported;
   private boolean primaryKeyJoin;
   private boolean primaryKeyExport;
+  private boolean embeddedAllowEmpty;
   private DeployBeanEmbedded deployEmbedded;
   private String columnPrefix;
 
@@ -103,6 +104,14 @@ public final class DeployBeanPropertyAssocOne<T> extends DeployBeanPropertyAssoc
     }
   }
 
+  public void setEmbeddedAllowEmpty(boolean allowEmpty) {
+    this.embeddedAllowEmpty = allowEmpty;
+  }
+
+  public boolean isEmbeddedAllowEmpty() {
+    return embeddedAllowEmpty;
+  }
+
   public void setColumnPrefix(String columnPrefix) {
     this.columnPrefix = columnPrefix;
   }

ebean-core/src/main/java/io/ebeaninternal/server/deploy/parse/AnnotationAssocManys.java

@@ -89,6 +89,11 @@ final class AnnotationAssocManys extends AnnotationAssoc {
     ManyToMany manyToMany = get(prop, ManyToMany.class);
     if (manyToMany != null) {
       readToMany(manyToMany, prop);
+      OrderColumn orderColumn = get(prop, OrderColumn.class);
+      if (orderColumn != null) {
+        // ManyToMany order value is stored on the intersection table (not the target bean)
+        prop.setOrderColumn(new DeployOrderColumn(orderColumn));
+      }
     }
     ElementCollection elementCollection = get(prop, ElementCollection.class);
     if (elementCollection != null) {
@@ -177,6 +182,11 @@ final class AnnotationAssocManys extends AnnotationAssoc {
     if (!elementCollection.targetClass().equals(void.class)) {
       prop.setTargetType(elementCollection.targetClass());
     }
+    OrderColumn orderColumn = get(prop, OrderColumn.class);
+    if (orderColumn != null) {
+      prop.setOrderColumn(new DeployOrderColumn(orderColumn));
+      prop.setFetchOrderBy(DeployOrderColumn.LOGICAL_NAME);
+    }
     Column column = prop.getMetaAnnotation(Column.class);
     if (column != null) {
       prop.setDbColumn(column.name());
@@ -268,6 +278,11 @@ final class AnnotationAssocManys extends AnnotationAssoc {
 
     elementDescriptor.setName(prop.toString());
     factory.createUnidirectional(elementDescriptor, prop.getOwningType(), beanTable, prop.getTableJoin());
+    if (prop.hasOrderColumn()) {
+      // create the synthetic order property on the element descriptor - the element descriptor
+      // is not registered in deployInfoMap so this can't go through the usual OneToMany path
+      factory.makeOrderColumn(prop, elementDescriptor);
+    }
     prop.setElementDescriptor(factory.createElementDescriptor(elementDescriptor, prop.getManyType(), scalar));
   }
 

ebean-core/src/main/java/io/ebeaninternal/server/deploy/parse/AnnotationAssocOnes.java

@@ -245,6 +245,13 @@ final class AnnotationAssocOnes extends AnnotationAssoc {
     } catch (NoSuchMethodError e) {
       // using standard JPA API without prefix option, maybe in EE container
     }
+    try {
+      if (!embedded.nullable()) {
+        prop.setEmbeddedAllowEmpty(true);
+      }
+    } catch (NoSuchMethodError e) {
+      // older persistence-api without nullable() extension
+    }
     readEmbeddedAttributeOverrides(prop);
   }
 

ebean-core/src/main/java/io/ebeaninternal/server/el/ElPropertyChain.java

@@ -42,17 +42,19 @@ public final class ElPropertyChain implements ElPropertyValue {
   private final ScalarType<?> scalarType;
   private final ElPropertyValue lastElPropertyValue;
 
-  public ElPropertyChain(boolean containsMany, boolean embedded, String expression, ElPropertyValue[] chain) {
-    this.containsMany = containsMany;
+  public ElPropertyChain(String expression, boolean containsMany, boolean embedded, ElPropertyValue[] chain) {
     this.chain = chain;
     this.expression = expression;
+    this.containsMany = containsMany;
+
     int dotPos = expression.lastIndexOf('.');
     if (dotPos > -1) {
       this.name = expression.substring(dotPos + 1);
       if (embedded) {
+        // embedded segments are transparent (share parent table) — strip the embedded
+        // segment from the prefix so the alias points to the parent join, not the embedded
         int embPos = expression.lastIndexOf('.', dotPos - 1);
         this.prefix = embPos == -1 ? null : expression.substring(0, embPos);
-
       } else {
         this.prefix = expression.substring(0, dotPos);
       }
@@ -61,19 +63,18 @@ public final class ElPropertyChain implements ElPropertyValue {
       this.name = expression;
     }
 
-    this.assocId = chain[chain.length - 1].isAssocId();
-
-    this.last = chain.length - 1;
-    this.lastBeanProperty = chain[chain.length - 1].beanProperty();
+    this.last = this.chain.length - 1;
+    this.lastElPropertyValue = this.chain[this.last];
+    this.assocId = this.lastElPropertyValue.isAssocId();
+    this.lastBeanProperty = lastElPropertyValue.beanProperty();
     if (lastBeanProperty != null) {
       this.scalarType = lastBeanProperty.scalarType();
     } else {
       // case for nested compound type (non-scalar)
       this.scalarType = null;
     }
-    this.lastElPropertyValue = chain[chain.length - 1];
-    this.placeHolder = placeHolder(prefix, lastElPropertyValue, false);
-    this.placeHolderEncrypted = placeHolder(prefix, lastElPropertyValue, true);
+    this.placeHolder = placeHolder(this.prefix, lastElPropertyValue, false);
+    this.placeHolderEncrypted = placeHolder(this.prefix, lastElPropertyValue, true);
   }
 
   @Override

ebean-core/src/main/java/io/ebeaninternal/server/el/ElPropertyChainBuilder.java

@@ -17,14 +17,13 @@ public final class ElPropertyChainBuilder {
 
   private final String expression;
   private final List<ElPropertyValue> chain = new ArrayList<>();
-  private boolean embedded;
-  private boolean containsMany;
+  private boolean containsMany = false;
+  private boolean embedded = false;
 
   /**
    * Create with the original expression.
    */
-  public ElPropertyChainBuilder(boolean embedded, String expression) {
-    this.embedded = embedded;
+  public ElPropertyChainBuilder(String expression) {
     this.expression = expression;
   }
 
@@ -32,14 +31,18 @@ public final class ElPropertyChainBuilder {
     return containsMany;
   }
 
-  public void setContainsMany() {
-    this.containsMany = true;
-  }
-
   public String expression() {
     return expression;
   }
 
+  /**
+   * Mark the chain as going through an embedded property.
+   * This affects how the prefix (table alias) is computed for SQL generation.
+   */
+  public void setEmbedded(boolean embedded) {
+    this.embedded = embedded;
+  }
+
   /**
    * Add a ElGetValue element to the chain.
    */
@@ -48,6 +51,9 @@ public final class ElPropertyChainBuilder {
       throw new NullPointerException("element null in expression " + expression);
     }
     chain.add(element);
+    if (element.containsMany()) {
+      containsMany = true;
+    }
     return this;
   }
 
@@ -55,13 +61,6 @@ public final class ElPropertyChainBuilder {
    * Build the immutable ElGetChain from the build information.
    */
   public ElPropertyChain build() {
-    return new ElPropertyChain(containsMany, embedded, expression, chain.toArray(new ElPropertyValue[0]));
-  }
-
-  /**
-   * Permits to set whole chain as embedded when the leaf is embedded
-   */
-  public void setEmbedded(boolean embedded) {
-    this.embedded = embedded;
+    return new ElPropertyChain(expression, containsMany, embedded, chain.toArray(new ElPropertyValue[0]));
   }
 }

ebean-core/src/main/java/io/ebeaninternal/server/el/ElPropertyDeploy.java

@@ -91,4 +91,16 @@ public interface ElPropertyDeploy extends SpiQueryManyJoin {
   default String fetchOrderBy() {
     return beanProperty().fetchOrderBy();
   }
+
+  @Override
+  default boolean hasIntersectionOrderColumn() {
+    BeanProperty prop = beanProperty();
+    return prop instanceof io.ebeaninternal.server.deploy.BeanPropertyAssocMany
+      && prop.hasIntersectionOrderColumn();
+  }
+
+  @Override
+  default String intersectionOrderColumn() {
+    return beanProperty().intersectionOrderColumn();
+  }
 }

ebean-core/src/main/java/io/ebeaninternal/server/expression/DefaultExpressionList.java

@@ -254,17 +254,27 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
 
   @Override
   public Query<T> asOf(Timestamp asOf) {
-    return query.asOf(asOf);
+    return query().asOf(asOf);
   }
 
   @Override
   public Query<T> asDraft() {
-    return query.asDraft();
+    return query().asDraft();
   }
 
   @Override
   public <D> DtoQuery<D> asDto(Class<D> dtoClass) {
-    return query.asDto(dtoClass);
+    return query().asDto(dtoClass);
+  }
+
+  @Override
+  public <D> MappedQuery<D> mapTo(Class<D> dtoType) {
+    return query().mapTo(dtoType);
+  }
+
+  @Override
+  public <D> MappedQuery<D> mapTo(Class<D> dtoType, DtoMapper<T, D> mapper) {
+    return query().mapTo(dtoType, mapper);
   }
 
   @Override
@@ -328,6 +338,11 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
     return query.delete();
   }
 
+  @Override
+  public int deletePermanent() {
+    return query.deletePermanent();
+  }
+
   @Override
   public int update() {
     return query.update();
@@ -1320,6 +1335,24 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
     return null;
   }
 
+  /**
+   * Return a "propertyName: value" description when this expression list is a single
+   * simple equality predicate (a candidate natural/unique key), otherwise null.
+   * <p>
+   * Used to build a decent default message for {@code findOneOrThrow()} when the query
+   * isn't a simple find-by-id.
+   */
+  @Nullable
+  public String singleEqDescription() {
+    if (list.size() == 1 && list.get(0) instanceof SimpleExpression) {
+      SimpleExpression simple = (SimpleExpression) list.get(0);
+      if (simple.isOpEquals()) {
+        return simple.getPropName() + ": " + simple.getValue();
+      }
+    }
+    return null;
+  }
+
   @Override
   public ExpressionList<T> clear() {
     list.clear();

ebean-core/src/main/java/io/ebeaninternal/server/expression/JunctionExpression.java

@@ -342,6 +342,11 @@ final class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expr
     return exprList.delete();
   }
 
+  @Override
+  public int deletePermanent() {
+    return exprList.deletePermanent();
+  }
+
   @Override
   public int update() {
     return exprList.update();
@@ -362,6 +367,16 @@ final class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expr
     return exprList.asDto(dtoClass);
   }
 
+  @Override
+  public <D> MappedQuery<D> mapTo(Class<D> dtoType) {
+    return exprList.mapTo(dtoType);
+  }
+
+  @Override
+  public <D> MappedQuery<D> mapTo(Class<D> dtoType, DtoMapper<T, D> mapper) {
+    return exprList.mapTo(dtoType, mapper);
+  }
+
   @Override
   public UpdateQuery<T> asUpdate() {
     return exprList.asUpdate();

ebean-core/src/main/java/io/ebeaninternal/server/persist/DefaultPersister.java

@@ -481,7 +481,7 @@ public final class DefaultPersister implements Persister {
         saveAssocOne(request);
       }
       request.executeOrQueue();
-      if (request.isPersistCascade()) {
+      if (request.isPersistCascade() && !request.isInsertConflictSkipped()) {
         // save any associated List held beans
         saveAssocMany(request);
       }
@@ -907,6 +907,11 @@ public final class DefaultPersister implements Persister {
    * </p>
    */
   private int delete(PersistRequestBean<?> request) {
+    // fire preDelete now, before cascading to children/many's so that the
+    // BeanPersistController/Adapter still sees the bean's collections and
+    // relationships as they are prior to the cascade delete
+    request.controllerPreDelete();
+
     DeleteUnloadedForeignKeys unloadedForeignKeys = null;
     if (request.isPersistCascade()) {
       // delete children first ... register the

ebean-core/src/main/java/io/ebeaninternal/server/persist/SaveManyBeans.java

@@ -256,6 +256,12 @@ final class SaveManyBeans extends SaveManyBase {
   }
 
   private void saveAssocManyIntersection(boolean queue) {
+    if (many.hasIntersectionOrderColumn()) {
+      // With @OrderColumn the position of every row can change on any add/remove/reorder so
+      // we always delete all intersection rows and reinsert them in the current list order.
+      saveAssocManyIntersectionOrdered(queue);
+      return;
+    }
     final boolean vanillaCollection = !(value instanceof BeanCollection<?>);
     if (vanillaCollection || forcedUpdate) {
       // delete all intersection rows and then treat all
@@ -292,6 +298,17 @@ final class SaveManyBeans extends SaveManyBase {
       manyValue.modifyReset();
     }
 
+    if (!insertedParent) {
+      // only fire controller when the intersection actually changes:
+      // vanillaCollection/forcedUpdate always do a full replace,
+      // tracked BeanCollection fires only when additions or removals exist
+      boolean intersectionChanged = vanillaCollection || forcedUpdate
+          || (additions != null && !additions.isEmpty())
+          || (deletions != null && !deletions.isEmpty());
+      if (intersectionChanged) {
+        request.preManyToManyUpdate();
+      }
+    }
     transaction.depth(+1);
     if (deletions != null && !deletions.isEmpty()) {
       for (Object other : deletions) {
@@ -329,6 +346,53 @@ final class SaveManyBeans extends SaveManyBase {
     transaction.depth(-1);
   }
 
+  /**
+   * Save the ManyToMany intersection rows for a property with an {@code @OrderColumn}.
+   * <p>
+   * Unlike the standard diff based save (additions/removals), this always deletes all existing
+   * intersection rows for the parent and reinserts every current entry in list order, binding
+   * the sequential order index. This is required because a pure reorder (no add/remove) would
+   * not otherwise be detected/persisted, and there is no per-row place (unlike OneToMany/
+   * ElementCollection) to compare an existing 'loaded' order against - the order value lives on
+   * the intersection row, not on the target bean.
+   */
+  private void saveAssocManyIntersectionOrdered(boolean queue) {
+    if (value == null) {
+      return;
+    }
+    Collection<?> current;
+    if (value instanceof Map<?, ?>) {
+      current = ((Map<?, ?>) value).values();
+    } else if (value instanceof Collection<?>) {
+      current = (Collection<?>) value;
+    } else {
+      throw new PersistenceException("Unhandled ManyToMany type " + value.getClass().getName() + " for " + many.fullName());
+    }
+    if (value instanceof BeanCollection<?>) {
+      BeanCollection<?> manyValue = (BeanCollection<?>) value;
+      setListenMode(manyValue, many);
+      manyValue.modifyReset();
+    }
+    if (!insertedParent) {
+      request.preManyToManyUpdate();
+      persister.deleteManyIntersection(parentBean, many, transaction, publish, queue);
+    }
+    String orderColumn = many.intersectionOrderColumn();
+    transaction.depth(+1);
+    int position = 0;
+    for (Object other : current) {
+      EntityBean otherBean = (EntityBean) other;
+      if (!many.hasImportedId(otherBean)) {
+        throw new PersistenceException("ManyToMany bean does not have an Id value? " + otherBean);
+      }
+      IntersectionRow intRow = many.buildManyToManyMapBean(parentBean, otherBean, publish);
+      intRow.put(orderColumn, position++);
+      SpiSqlUpdate sqlInsert = intRow.createInsert(server);
+      persister.executeOrQueue(sqlInsert, transaction, queue, BatchControl.INSERT_QUEUE);
+    }
+    transaction.depth(-1);
+  }
+
   private boolean isChangedProperty() {
     return request.isChangedProperty(many.propertyIndex());
   }