HHH-18629 Fix inconsistent column alias generated while result class is used for placeholder

Author: quaff

hibernate-core/src/main/java/org/hibernate/internal/AbstractSharedSessionContract.java

@@ -969,7 +969,8 @@ else if ( List.class.equals( resultClass ) ) {
 			query.setTupleTransformer( NativeQueryListTransformer.INSTANCE );
 		}
 		else if ( getFactory().getMappingMetamodel().isEntityClass( resultClass ) ) {
-			query.addEntity( resultClass, LockMode.READ );
+			// use empty string as tableAlias to identify it as implicit
+			query.addEntity( "", resultClass, LockMode.READ );
 		}
 		else if ( resultClass != Object.class && resultClass != Object[].class ) {
 			if ( isClass( resultClass ) && !hasJavaTypeDescriptor( resultClass ) ) {

hibernate-core/src/main/java/org/hibernate/query/results/ResultSetMapping.java

@@ -77,6 +77,11 @@ public interface ResultSetMapping extends JdbcValuesMappingProducer {
 	 */
 	void addResultBuilder(ResultBuilder resultBuilder);
 
+	/**
+	 * Remove a builder
+	 */
+	void removeResultBuilder(ResultBuilder resultBuilder);
+
 	/**
 	 * Add a legacy fetch builder
 	 */

hibernate-core/src/main/java/org/hibernate/query/results/ResultSetMappingImpl.java

@@ -137,6 +137,11 @@ public void addResultBuilder(ResultBuilder resultBuilder) {
 		resultBuilders.add( resultBuilder );
 	}
 
+	@Override
+	public void removeResultBuilder(ResultBuilder resultBuilder) {
+		resultBuilders.remove( resultBuilder );
+	}
+
 	@Override
 	public void addLegacyFetchBuilder(DynamicFetchBuilderLegacy fetchBuilder) {
 		final Map<String, DynamicFetchBuilderLegacy> existingFetchBuildersByOwner;

hibernate-core/src/main/java/org/hibernate/query/sql/internal/NativeQueryImpl.java

@@ -942,6 +942,23 @@ public NativeQueryImplementor<R> addScalar(int position, Class<?> type) {
 	}
 
 	protected NativeQueryImplementor<R> registerBuilder(ResultBuilder builder) {
+		// remove implicit ResultBuilder if explicit one provided
+		if ( builder instanceof DynamicResultBuilderEntityCalculated dynamicBuilder ) {
+			ResultBuilder implicitResultBuilder = null;
+			for ( ResultBuilder existing : resultSetMapping.getResultBuilders() ) {
+				if ( existing instanceof DynamicResultBuilderEntityCalculated existingDynamicBuilder ) {
+					if ( "".equals( existingDynamicBuilder.getTableAlias() ) // implicit
+							&& existingDynamicBuilder.getNavigablePath().equals( dynamicBuilder.getNavigablePath() )
+							&& existingDynamicBuilder.getEntityMapping().equals( dynamicBuilder.getEntityMapping() ) ) {
+						implicitResultBuilder = existingDynamicBuilder;
+						break;
+					}
+				}
+			}
+			if ( implicitResultBuilder != null ) {
+				resultSetMapping.removeResultBuilder( implicitResultBuilder );
+			}
+		}
 		resultSetMapping.addResultBuilder( builder );
 		return this;
 	}