#1933 - ENH: Add DtoQuery.usingTransaction(Transaction) ... dto query with supplied transaction

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

@@ -136,4 +136,8 @@ public interface DtoQuery<T> {
    */
   DtoQuery<T> setBufferFetchSizeHint(int bufferFetchSizeHint);
 
+  /**
+   * Use the explicit transaction to execute the query.
+   */
+  DtoQuery<T> usingTransaction(Transaction transaction);
 }

src/main/java/io/ebeaninternal/api/SpiDtoQuery.java

@@ -2,6 +2,7 @@ package io.ebeaninternal.api;
 
 import io.ebean.DtoQuery;
 import io.ebean.ProfileLocation;
+import io.ebean.Transaction;
 import io.ebeaninternal.server.dto.DtoMappingRequest;
 import io.ebeaninternal.server.dto.DtoQueryPlan;
 
@@ -65,4 +66,9 @@ public interface SpiDtoQuery<T> extends DtoQuery<T>, SpiSqlBinding {
    */
   SpiQuery<?> getOrmQuery();
 
+  /**
+   * Return the explicit transaction used to execute the query.
+   */
+  Transaction getTransaction();
+
 }

src/main/java/io/ebeaninternal/server/core/DtoQueryRequest.java

@@ -32,7 +32,7 @@ public final class DtoQueryRequest<T> extends AbstractSqlQueryRequest {
   private DataReader dataReader;
 
   DtoQueryRequest(SpiEbeanServer server, DtoQueryEngine engine, SpiDtoQuery<T> query) {
-    super(server, query, null);
+    super(server, query, query.getTransaction());
     this.queryEngine = engine;
     this.query = query;
     query.obtainLocation();

src/main/java/io/ebeaninternal/server/querydefn/DefaultDtoQuery.java

@@ -2,6 +2,7 @@ package io.ebeaninternal.server.querydefn;
 
 import io.ebean.DtoQuery;
 import io.ebean.ProfileLocation;
+import io.ebean.Transaction;
 import io.ebeaninternal.api.BindParams;
 import io.ebeaninternal.api.SpiDtoQuery;
 import io.ebeaninternal.api.SpiEbeanServer;
@@ -47,6 +48,8 @@ public class DefaultDtoQuery<T> implements SpiDtoQuery<T> {
    */
   private final BindParams bindParams = new BindParams();
 
+  private Transaction transaction;
+
   /**
    * Create given an underlying ORM query.
    */
@@ -88,6 +91,12 @@ public class DefaultDtoQuery<T> implements SpiDtoQuery<T> {
     descriptor.putQueryPlan(planKey, plan);
   }
 
+  @Override
+  public DtoQuery<T> usingTransaction(Transaction transaction) {
+    this.transaction = transaction;
+    return this;
+  }
+
   @Override
   public void findEach(Consumer<T> consumer) {
     server.findDtoEach(this, consumer);
@@ -148,6 +157,11 @@ public class DefaultDtoQuery<T> implements SpiDtoQuery<T> {
     return ormQuery;
   }
 
+  @Override
+  public Transaction getTransaction() {
+    return transaction;
+  }
+
   @Override
   public DtoQuery<T> setRelaxedMode() {
     this.relaxedMode = true;

src/test/java/org/tests/basic/TestQueryUsingConnection.java

@@ -14,6 +14,7 @@ import java.sql.Connection;
 import java.sql.SQLException;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertEquals;
 
 public class TestQueryUsingConnection extends BaseTestCase {
 
@@ -51,6 +52,15 @@ public class TestQueryUsingConnection extends BaseTestCase {
 
       DB.getDefault().insert(x, transaction);
 
+      final CountryDto dto = DB.findDto(CountryDto.class, "select code, name from o_country where code=?")
+        .usingTransaction(transaction)
+        .setParameter(1, "xx")
+        .findOne();
+
+      assertThat(dto).isNotNull();
+      assertEquals("xx", dto.code);
+      assertEquals("WillRollThisBack", dto.name);
+
       final int count = DB.find(Country.class)
         .usingTransaction(transaction)
         .findCount();
@@ -63,4 +73,14 @@ public class TestQueryUsingConnection extends BaseTestCase {
     }
 
   }
+
+  public static class CountryDto {
+    final String code;
+    final String name;
+
+    public CountryDto(String code, String name) {
+      this.code = code;
+      this.name = name;
+    }
+  }
 }