#866 - Fix RawSql mapping such that it automatically maps foreign key columns

src/main/java/com/avaje/ebeaninternal/server/query/CQueryBuilder.java

@@ -363,8 +363,15 @@ class CQueryBuilder {
       RawSql.ColumnMapping.Column column = it.next();
       String propertyName = column.getPropertyName();
       if (!RawSqlBuilder.IGNORE_COLUMN.equals(propertyName)) {
-
         ElPropertyValue el = descriptor.getElGetValue(propertyName);
+        if (el == null && propertyName.endsWith("Id")) {
+          // try default naming convention for foreign key columns
+          String foreignIdPath = assocOneIdPath(propertyName);
+          el = descriptor.getElGetValue(foreignIdPath);
+          if (el != null) {
+            propertyName = foreignIdPath;
+          }
+        }
         if (el == null) {
           throw new PersistenceException("Property [" + propertyName + "] not found on " + descriptor.getFullName());
         } else {
@@ -404,6 +411,13 @@ class CQueryBuilder {
     return new SqlTreeBuilder(request, predicates, detail, rawNoId).build();
   }
 
+  /**
+   * Return a path for a foreign key property using the default naming convention.
+   */
+  private String assocOneIdPath(String propertyName) {
+    return propertyName.substring(0, propertyName.length() - 2) + ".id";
+  }
+
   /**
    * Return the SQL response with row limiting (when not an update statement).
    */

src/main/java/com/avaje/ebeaninternal/server/query/CQueryPlanRawSql.java

@@ -35,7 +35,13 @@ class CQueryPlanRawSql extends CQueryPlan {
 
     // set the resultSet index positions for the property expressions
     for (int i = 0; i < chain.size(); i++) {
-      indexPositions[i] = 1 + columnMapping.getIndexPosition(chain.get(i));
+      String logicalPropertyPath = chain.get(i);
+      int mappedPosition = columnMapping.getIndexPosition(logicalPropertyPath);
+      if (mappedPosition == -1 && logicalPropertyPath.endsWith(".id")) {
+        // try a automatically mapped foreign key
+        mappedPosition = columnMapping.getIndexPosition(foreignKeyPath(logicalPropertyPath));
+      }
+      indexPositions[i] = 1 + mappedPosition;
     }
 
     // check and handle the case where a discriminator column for
@@ -51,4 +57,12 @@ class CQueryPlanRawSql extends CQueryPlan {
 
     return indexPositions;
   }
+
+  /**
+   * Return the path for a foreign key column that was automatically mapped.
+   */
+  private String foreignKeyPath(String logicalPropertyPath) {
+    // trim the .id and replace with Id ... to reverse the auto fk mapping earlier
+    return logicalPropertyPath.substring(0, logicalPropertyPath.length() - 3) + "Id";
+  }
 }