Use FK descriptor instead of target entity identifier

hibernate-core/src/main/java/org/hibernate/metamodel/internal/AbstractCompositeIdentifierMapping.java

@@ -16,6 +16,7 @@ import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.util.collections.CollectionHelper;
 import org.hibernate.metamodel.mapping.AttributeMapping;
+import org.hibernate.metamodel.mapping.ForeignKeyDescriptor;
 import org.hibernate.metamodel.mapping.SelectionConsumer;
 import org.hibernate.metamodel.mapping.SelectionMappings;
 import org.hibernate.metamodel.mapping.CompositeIdentifierMapping;
@@ -202,12 +203,9 @@ public abstract class AbstractCompositeIdentifierMapping
 			final AttributeMapping attributeMapping = attributeMappings.get( i );
 			final Object o = attributeMapping.getPropertyAccess().getGetter().get( value );
 			if ( attributeMapping instanceof ToOneAttributeMapping ) {
-				final EntityMappingType associatedEntityMappingType =
+				final ForeignKeyDescriptor fkDescriptor = ( (ToOneAttributeMapping) attributeMapping ).getForeignKeyDescriptor();
-						( (ToOneAttributeMapping) attributeMapping ).getAssociatedEntityMappingType();
+				final Object identifier = fkDescriptor.getAssociationKeyFromTarget( o, session );
-				final EntityIdentifierMapping identifierMapping =
+				span += fkDescriptor.forEachJdbcValue(
-						associatedEntityMappingType.getIdentifierMapping();
-				final Object identifier = identifierMapping.getIdentifier( o, session );
-				span += identifierMapping.forEachJdbcValue(
 						identifier,
 						clause,
 						span + offset,

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/ForeignKeyDescriptor.java

@@ -6,6 +6,7 @@
  */
 package org.hibernate.metamodel.mapping;
 
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.query.NavigablePath;
 import org.hibernate.sql.ast.SqlAstJoinType;
 import org.hibernate.sql.ast.spi.SqlAstCreationContext;
@@ -65,6 +66,8 @@ public interface ForeignKeyDescriptor extends VirtualModelPart {
 		return visitReferringColumns( offset, consumer );
 	}
 
+	Object getAssociationKeyFromTarget(Object targetObject, SharedSessionContractImplementor session);
+
 	int visitReferringColumns(int offset, SelectionConsumer consumer);
 
 	int visitTargetColumns(int offset, SelectionConsumer consumer);

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

@@ -331,11 +331,7 @@ public class CompoundNaturalIdMapping extends AbstractNaturalIdMapping implement
 			if ( attributeMapping instanceof ToOneAttributeMapping ) {
 				final ToOneAttributeMapping toOne = (ToOneAttributeMapping) attributeMapping;
 				final ForeignKeyDescriptor fKDescriptor = toOne.getForeignKeyDescriptor();
-
+				final Object keyValue = value == null ? null : fKDescriptor.disassemble( value, session );
-				final EntityMappingType associatedEntityMapping = toOne.getEntityMappingType();
-				final EntityIdentifierMapping associatedEntityMappingIdentifierMapping = associatedEntityMapping.getIdentifierMapping();
-
-				final Object keyValue = value == null ? null : associatedEntityMappingIdentifierMapping.getIdentifier( value, session );
 				fKDescriptor.breakDownJdbcValues( keyValue, valueConsumer, session );
 			}
 			else {

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

@@ -409,6 +409,16 @@ public class EmbeddedForeignKeyDescriptor implements ForeignKeyDescriptor, Model
 		);
 	}
 
+	@Override
+	public Object getAssociationKeyFromTarget(Object targetObject, SharedSessionContractImplementor session) {
+		// If the mapping type has an identifier type, that identifier is the key
+		if ( mappingType instanceof SingleAttributeIdentifierMapping ) {
+			return ( (SingleAttributeIdentifierMapping) mappingType ).getIdentifier( targetObject, session );
+		}
+		// Otherwise this is a key based on the target object i.e. without id-class
+		return targetObject;
+	}
+
 	@Override
 	public EntityMappingType findContainingEntityMapping() {
 		throw new UnsupportedOperationException();

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

@@ -899,7 +899,8 @@ public class MappingModelCreationHelper {
 		final Type keyType = bootValueMappingKey.getType();
 		final ModelPart fkTarget;
 		final String lhsPropertyName = collectionDescriptor.getCollectionType().getLHSPropertyName();
-		if ( lhsPropertyName == null ) {
+		final boolean isReferenceToPrimaryKey = lhsPropertyName == null;
+		if ( isReferenceToPrimaryKey ) {
 			fkTarget = collectionDescriptor.getOwnerEntityPersister().getIdentifierMapping();
 		}
 		else {
@@ -922,7 +923,8 @@ public class MappingModelCreationHelper {
 					new SimpleForeignKeyDescriptor(
 							keySelectionMapping,
 							simpleFkTarget,
-							( (PropertyBasedMapping) simpleFkTarget ).getPropertyAccess()
+							( (PropertyBasedMapping) simpleFkTarget ).getPropertyAccess(),
+							isReferenceToPrimaryKey
 					)
 			);
 		}
@@ -1045,7 +1047,8 @@ public class MappingModelCreationHelper {
 			final ForeignKeyDescriptor foreignKeyDescriptor = new SimpleForeignKeyDescriptor(
 					keySelectionMapping,
 					simpleFkTarget,
-					( (PropertyBasedMapping) simpleFkTarget ).getPropertyAccess()
+					( (PropertyBasedMapping) simpleFkTarget ).getPropertyAccess(),
+					bootValueMapping.isReferenceToPrimaryKey()
 			);
 			attributeMapping.setForeignKeyDescriptor( foreignKeyDescriptor );
 		}

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

@@ -342,7 +342,8 @@ public class PluralAttributeMappingImpl
 			return new SimpleForeignKeyDescriptor(
 					keySelectionMapping,
 					basicFkTargetPart,
-					( (PropertyBasedMapping) basicFkTargetPart ).getPropertyAccess()
+					( (PropertyBasedMapping) basicFkTargetPart ).getPropertyAccess(),
+					entityType.isReferenceToPrimaryKey()
 			);
 		}
 		else if ( fkTargetPart instanceof EmbeddableValuedModelPart ) {

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

@@ -24,6 +24,7 @@ import org.hibernate.metamodel.mapping.JdbcMapping;
 import org.hibernate.metamodel.mapping.MappingType;
 import org.hibernate.metamodel.model.domain.NavigableRole;
 import org.hibernate.property.access.spi.PropertyAccess;
+import org.hibernate.proxy.HibernateProxy;
 import org.hibernate.query.ComparisonOperator;
 import org.hibernate.query.NavigablePath;
 import org.hibernate.sql.ast.Clause;
@@ -53,15 +54,18 @@ public class SimpleForeignKeyDescriptor implements ForeignKeyDescriptor, BasicVa
 	private final SelectionMapping keySelectionMapping;
 	private final SelectionMapping targetSelectionMapping;
 	private final PropertyAccess propertyAccess;
+	private final boolean refersToPrimaryKey;
 	private AssociationKey associationKey;
 
 	public SimpleForeignKeyDescriptor(
 			SelectionMapping keySelectionMapping,
 			SelectionMapping targetSelectionMapping,
-			PropertyAccess propertyAccess) {
+			PropertyAccess propertyAccess,
+			boolean refersToPrimaryKey) {
 		this.keySelectionMapping = keySelectionMapping;
 		this.targetSelectionMapping = targetSelectionMapping;
 		this.propertyAccess = propertyAccess;
+		this.refersToPrimaryKey = refersToPrimaryKey;
 	}
 
 	@Override
@@ -264,7 +268,18 @@ public class SimpleForeignKeyDescriptor implements ForeignKeyDescriptor, BasicVa
 
 	@Override
 	public Object disassemble(Object value, SharedSessionContractImplementor session) {
-		return value == null ? null : propertyAccess.getGetter().get( value );
+		if ( value == null ) {
+			return null;
+		}
+		if ( refersToPrimaryKey && value instanceof HibernateProxy ) {
+			return ( (HibernateProxy) value ).getHibernateLazyInitializer().getIdentifier();
+		}
+		return propertyAccess.getGetter().get( value );
+	}
+
+	@Override
+	public Object getAssociationKeyFromTarget(Object targetObject, SharedSessionContractImplementor session) {
+		return disassemble( targetObject, session );
 	}
 
 	@Override

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

@@ -698,7 +698,7 @@ public class ToOneAttributeMapping
 
 	@Override
 	public int forEachJdbcValue(Object value, Clause clause, int offset, JdbcValuesConsumer consumer, SharedSessionContractImplementor session) {
-		return foreignKeyDescriptor.forEachJdbcValue(
+		return foreignKeyDescriptor.forEachDisassembledJdbcValue(
 				foreignKeyDescriptor.disassemble( value, session ),
 				clause,
 				offset,

hibernate-core/src/main/java/org/hibernate/query/sqm/internal/SqmUtil.java

@@ -18,9 +18,7 @@ import java.util.function.Function;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.metamodel.MappingMetamodel;
-import org.hibernate.metamodel.mapping.Bindable;
 import org.hibernate.metamodel.mapping.EntityIdentifierMapping;
-import org.hibernate.metamodel.mapping.JdbcMapping;
 import org.hibernate.metamodel.mapping.MappingModelExpressable;
 import org.hibernate.metamodel.mapping.internal.ToOneAttributeMapping;
 import org.hibernate.metamodel.model.domain.AllowableParameterType;
@@ -288,19 +286,7 @@ public class SqmUtil {
 				}
 				else if ( type instanceof ToOneAttributeMapping ) {
 					ToOneAttributeMapping association = (ToOneAttributeMapping) type;
-					if ( association.getReferencedPropertyName() == null ) {
+					bindValue = association.getForeignKeyDescriptor().getAssociationKeyFromTarget( bindValue, session );
-						bindValue = association.getEntityMappingType().getIdentifierMapping().getIdentifier(
-								bindValue,
-								session
-						);
-					}
-					else {
-						bindValue = association.getEntityMappingType()
-								.findAttributeMapping( association.getReferencedPropertyName() )
-								.getPropertyAccess()
-								.getGetter()
-								.get( bindValue );
-					}
 					mappingExpressable = association.getForeignKeyDescriptor();
 				}
 				else {