HHH-13725 - Implement ToOne Associations support

hibernate-core/src/main/java/org/hibernate/cfg/ToOneFkSecondPass.java

@@ -14,6 +14,7 @@ import org.hibernate.MappingException;
 import org.hibernate.boot.spi.MetadataBuildingContext;
 import org.hibernate.cfg.annotations.TableBinder;
 import org.hibernate.internal.util.StringHelper;
+import org.hibernate.mapping.Column;
 import org.hibernate.mapping.Component;
 import org.hibernate.mapping.KeyValue;
 import org.hibernate.mapping.ManyToOne;

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/MappingModelCreationHelper.java

@@ -16,6 +16,7 @@ import java.util.function.Consumer;
 import org.hibernate.LockMode;
 import org.hibernate.MappingException;
 import org.hibernate.NotYetImplementedFor6Exception;
+import org.hibernate.boot.model.naming.Identifier;
 import org.hibernate.collection.internal.StandardArraySemantics;
 import org.hibernate.collection.internal.StandardBagSemantics;
 import org.hibernate.collection.internal.StandardIdentifierBagSemantics;
@@ -913,6 +914,7 @@ public class MappingModelCreationHelper {
 
 		final ModelPart fkTarget;
 		if ( bootValueMapping.isReferenceToPrimaryKey() ) {
+			referencedEntityDescriptor.prepareMappingModel( creationProcess );
 			fkTarget = referencedEntityDescriptor.getIdentifierMapping();
 		}
 		else {
@@ -924,15 +926,26 @@ public class MappingModelCreationHelper {
 		if ( fkTarget instanceof BasicValuedModelPart ) {
 			final BasicValuedModelPart simpleFkTarget = (BasicValuedModelPart) fkTarget;
 
-			return new SimpleForeignKeyDescriptor(
+			final Iterator<Selectable> columnIterator = bootValueMapping.getColumnIterator();
-					creationProcess.getCreationContext()
+			String keyColumnExpression;
+			final Identifier identifier = creationProcess.getCreationContext()
 					.getBootstrapContext()
 					.getMetadataBuildingOptions()
 					.getPhysicalNamingStrategy().toPhysicalTableName(
 							bootValueMapping.getTable().getNameIdentifier(),
 							jdbcServices.getJdbcEnvironment()
-					).getText(),
+					);
-					bootValueMapping.getColumnIterator().next().getText( dialect ),
+
+			if ( columnIterator.hasNext() ) {
+				keyColumnExpression = columnIterator.next().getText( dialect );
+			}
+			else {
+				// case of ToOne with @PrimaryKeyJoinColumn
+				keyColumnExpression = identifier.getText();
+			}
+			return new SimpleForeignKeyDescriptor(
+					identifier.getText(),
+					keyColumnExpression,
 					simpleFkTarget.getContainingTableExpression(),
 					simpleFkTarget.getMappedColumnExpression(),
 					simpleFkTarget.getJdbcMapping()

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/SingularAssociationAttributeMapping.java

@@ -6,11 +6,7 @@
  */
 package org.hibernate.metamodel.mapping.internal;
 
-import java.util.ArrayList;
-import java.util.List;
-
 import org.hibernate.LockMode;
-import org.hibernate.NotYetImplementedFor6Exception;
 import org.hibernate.engine.FetchStrategy;
 import org.hibernate.engine.FetchTiming;
 import org.hibernate.metamodel.mapping.EntityMappingType;
@@ -27,15 +23,14 @@ import org.hibernate.sql.ast.spi.SqlAliasStemHelper;
 import org.hibernate.sql.ast.spi.SqlAstCreationContext;
 import org.hibernate.sql.ast.spi.SqlAstCreationState;
 import org.hibernate.sql.ast.spi.SqlExpressionResolver;
-import org.hibernate.sql.ast.spi.SqlSelection;
 import org.hibernate.sql.ast.tree.from.TableGroup;
 import org.hibernate.sql.ast.tree.from.TableGroupBuilder;
 import org.hibernate.sql.ast.tree.from.TableGroupJoin;
 import org.hibernate.sql.ast.tree.from.TableGroupJoinProducer;
 import org.hibernate.sql.ast.tree.from.TableReferenceCollector;
+import org.hibernate.sql.ast.tree.predicate.Predicate;
 import org.hibernate.sql.results.internal.domain.entity.DelayedEntityFetch;
 import org.hibernate.sql.results.internal.domain.entity.EntityFetchImpl;
-import org.hibernate.sql.results.spi.DomainResult;
 import org.hibernate.sql.results.spi.DomainResultCreationState;
 import org.hibernate.sql.results.spi.Fetch;
 import org.hibernate.sql.results.spi.FetchParent;
@@ -78,7 +73,7 @@ public class SingularAssociationAttributeMapping extends AbstractSingularAttribu
 
 	@Override
 	public EntityMappingType getEntityMappingType() {
-		return (EntityMappingType)getMappedTypeDescriptor();
+		return getMappedTypeDescriptor();
 	}
 
 	@Override
@@ -96,6 +91,7 @@ public class SingularAssociationAttributeMapping extends AbstractSingularAttribu
 			TableGroup lhsTableGroup = sqlAstCreationState.getFromClauseAccess()
 					.getTableGroup( fetchParent.getNavigablePath() );
 
+			if ( sqlAstCreationState.getFromClauseAccess().findTableGroup( fetchablePath ) == null ) {
 				// todo (6.0) : determine the correct JoinType
 				final TableGroupJoin tableGroupJoin = createTableGroupJoin(
 						fetchablePath,
@@ -114,6 +110,7 @@ public class SingularAssociationAttributeMapping extends AbstractSingularAttribu
 						fetchablePath,
 						tableGroupJoin.getJoinedGroup()
 				);
+			}
 
 			return new EntityFetchImpl(
 					fetchParent,
@@ -182,6 +179,15 @@ public class SingularAssociationAttributeMapping extends AbstractSingularAttribu
 
 		lhs.addTableGroupJoin( tableGroupJoin );
 
+		final Predicate predicate = foreignKeyDescriptor.generateJoinPredicate(
+				lhs,
+				tableGroup,
+				joinType,
+				sqlExpressionResolver,
+				creationContext
+		);
+		tableGroupJoin.applyPredicate( predicate );
+
 		return tableGroupJoin;
 	}
 

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -6198,8 +6198,6 @@ public abstract class AbstractEntityPersister
 			accessOptimizer = null;
 		}
 
-		final SessionFactoryImplementor sessionFactory = creationContext.getSessionFactory();
-
 		if ( isMultiTable() ) {
 			sqmMultiTableMutationStrategy = interpretSqmMultiTableStrategy(
 					this,

hibernate-core/src/main/java/org/hibernate/sql/ast/tree/from/AbstractColumnReferenceQualifier.java

@@ -56,6 +56,7 @@ public abstract class AbstractColumnReferenceQualifier implements ColumnReferenc
 				return tableJoin.getJoinedTableReference();
 			}
 		}
+
 		return null;
 	}
 

hibernate-core/src/main/java/org/hibernate/sql/ast/tree/from/StandardTableGroup.java

@@ -64,10 +64,16 @@ public class StandardTableGroup extends AbstractTableGroup {
 		if ( tableReference == null ) {
 			for ( TableReferenceJoin tableJoin : tableJoins ) {
 				if ( tableJoin.getJoinedTableReference().getTableExpression().equals( tableExpression ) ) {
-					tableReference = tableJoin.getJoinedTableReference();
+					return tableJoin.getJoinedTableReference();
 				}
 			}
 		}
+		for ( TableGroupJoin tableGroupJoin : getTableGroupJoins() ) {
+			final TableReference primaryTableReference = tableGroupJoin.getJoinedGroup().getPrimaryTableReference();
+			if ( primaryTableReference.getTableExpression().equals( tableExpression ) ) {
+				return primaryTableReference;
+			}
+		}
 		return tableReference;
 	}
 }

hibernate-core/src/main/java/org/hibernate/sql/results/internal/domain/entity/DelayedEntityFetch.java

@@ -6,19 +6,16 @@
  */
 package org.hibernate.sql.results.internal.domain.entity;
 
-import java.util.ArrayList;
 import java.util.function.Consumer;
 
 import org.hibernate.LockMode;
 import org.hibernate.NotYetImplementedFor6Exception;
-import org.hibernate.engine.spi.CollectionKey;
 import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.metamodel.mapping.internal.SingularAssociationAttributeMapping;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.query.NavigablePath;
 import org.hibernate.sql.results.internal.domain.AbstractFetchParentAccess;
 import org.hibernate.sql.results.spi.AssemblerCreationState;
-import org.hibernate.sql.results.spi.DomainResult;
 import org.hibernate.sql.results.spi.DomainResultAssembler;
 import org.hibernate.sql.results.spi.DomainResultCreationState;
 import org.hibernate.sql.results.spi.EntityInitializer;
@@ -81,7 +78,7 @@ public class DelayedEntityFetch implements Fetch {
 			FetchParentAccess parentAccess,
 			Consumer<Initializer> collector,
 			AssemblerCreationState creationState) {
-		EntityInitializer entityInitializer = new DelayedEntityFectInitializer(
+		EntityInitializer entityInitializer = new DelayedEntityFetchInitializer(
 				parentAccess,
 				navigablePath,
 				(EntityPersister) fetchedAttribute.getMappedTypeDescriptor()
@@ -91,7 +88,7 @@ public class DelayedEntityFetch implements Fetch {
 
 	}
 
-	private static class DelayedEntityFectInitializer extends AbstractFetchParentAccess implements EntityInitializer {
+	private static class DelayedEntityFetchInitializer extends AbstractFetchParentAccess implements EntityInitializer {
 
 		private final FetchParentAccess parentAccess;
 		private final NavigablePath navigablePath;
@@ -99,7 +96,7 @@ public class DelayedEntityFetch implements Fetch {
 
 		private Object entityInstance;
 
-		protected DelayedEntityFectInitializer(
+		protected DelayedEntityFetchInitializer(
 				FetchParentAccess parentAccess,
 				NavigablePath fetchedNavigable,
 				EntityPersister concreteDescriptor

hibernate-core/src/main/java/org/hibernate/sql/results/internal/domain/entity/EntityFetchImpl.java

@@ -52,8 +52,12 @@ public class EntityFetchImpl implements Fetch {
 		this.navigablePath = navigablePath;
 		this.fkResult = fkResult;
 
-		entityResult = new EntityResultImpl( navigablePath,
+		entityResult = new EntityResultImpl(
-											 (EntityValuedModelPart) fetchedAttribute.getMappedTypeDescriptor(), null, creationState );
+				navigablePath,
+				(EntityValuedModelPart) fetchedAttribute.getMappedTypeDescriptor(),
+				null,
+				creationState
+		);
 
 	}
 

hibernate-core/src/test/java/org/hibernate/orm/test/sql/exec/ManyToOneTest.java

@@ -75,6 +75,7 @@ public class ManyToOneTest {
 				session -> {
 					SimpleEntity simpleEntity = new SimpleEntity();
 					simpleEntity.setId( 1 );
+					simpleEntity.setName( "Fab" );
 					session.save( simpleEntity );
 					OtherEntity otherEntity = new OtherEntity();
 					otherEntity.setId( 2 );