HHH-9055 - Binding support for IdClass and MapsId needs a complete review

hibernate-core/src/main/java/org/hibernate/loader/JoinWalker.java

@@ -549,15 +549,9 @@ public class JoinWalker {
 		final Type idType = persister.getIdentifierType();
 		if ( idType.isComponentType() ) {
 			final CompositeType cidType = (CompositeType) idType;
-			if ( cidType.isEmbedded() ) {
+			if ( persister.getEntityMetamodel().getIdentifierProperty().isVirtual() ) {
-				// we have an embedded composite identifier.  Most likely we need to process the composite
+				// we have a non-aggregated composite identifier.  We need to process
-				// properties separately, although there is an edge case where the identifier is really
+				// the composite sub-properties separately
-				// a simple identifier (single value) wrapped in a JPA @IdClass or even in the case of a
-				// a simple identifier (single value) wrapped in a Hibernate composite type.
-				//
-				// We really do not have a built-in method to determine that.  However, generally the
-				// persister would report that there is single, physical identifier property which is
-				// explicitly at odds with the notion of "embedded composite".  So we use that for now
 				if ( persister.getEntityMetamodel().getIdentifierProperty().isEmbedded() ) {
 					walkComponentTree(
 							cidType,
@@ -570,6 +564,27 @@ public class JoinWalker {
 					);
 				}
 			}
+//			if ( cidType.isEmbedded() ) {
+//				// we have an embedded composite identifier.  Most likely we need to process the composite
+//				// properties separately, although there is an edge case where the identifier is really
+//				// a simple identifier (single value) wrapped in a JPA @IdClass or even in the case of a
+//				// a simple identifier (single value) wrapped in a Hibernate composite type.
+//				//
+//				// We really do not have a built-in method to determine that.  However, generally the
+//				// persister would report that there is single, physical identifier property which is
+//				// explicitly at odds with the notion of "embedded composite".  So we use that for now
+//				if ( persister.getEntityMetamodel().getIdentifierProperty().isEmbedded() ) {
+//					walkComponentTree(
+//							cidType,
+//							-1,
+//							0,
+//							persister,
+//							alias,
+//							path,
+//							currentDepth
+//					);
+//				}
+//			}
 		}
 	}
 

hibernate-core/src/main/java/org/hibernate/metamodel/spi/binding/EntityBinding.java

@@ -538,7 +538,7 @@ public class EntityBinding extends AbstractAttributeBindingContainer implements
 				getPathBase(),
 				idAttributeBindings
 		);
-		registerAttributeBinding( binding );
+//		registerAttributeBinding( binding );
 		return binding;
 	}
 

hibernate-core/src/main/java/org/hibernate/metamodel/spi/binding/EntityIdentifier.java

@@ -48,9 +48,15 @@ import static org.hibernate.id.EntityIdentifierNature.NON_AGGREGATED_COMPOSITE;
 import static org.hibernate.id.EntityIdentifierNature.SIMPLE;
 
 /**
- * Hold information about the entity identifier.  At a high-level, can be one of 2-types:<ul>
+ * Hold information about the entity identifier.  At a high-level, can be one of
- *     <li>single-attribute identifier - this includes both simple identifiers and aggregated composite identifiers</li>
+ * 2 types:<ul>
- *     <li>multiple-attribute identifier - non-aggregated composite identifiers</li>
+ *     <li>
+ *         single-attribute identifier - this includes both simple identifiers
+ *         and aggregated composite identifiers
+ *     </li>
+ *     <li>
+ *         multi-attribute identifier - non-aggregated composite identifiers
+ *     </li>
  * </ul>
  *
  * @author Steve Ebersole

hibernate-core/src/main/java/org/hibernate/tuple/PropertyFactory.java

@@ -35,6 +35,7 @@ import org.hibernate.engine.spi.CascadeStyles;
 import org.hibernate.engine.spi.IdentifierValue;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.VersionValue;
+import org.hibernate.id.EntityIdentifierNature;
 import org.hibernate.id.IdentifierGenerator;
 import org.hibernate.internal.util.ReflectHelper;
 import org.hibernate.mapping.KeyValue;
@@ -58,6 +59,7 @@ import org.hibernate.tuple.entity.EntityBasedBasicAttribute;
 import org.hibernate.tuple.entity.EntityBasedCompositionAttribute;
 import org.hibernate.tuple.entity.VersionProperty;
 import org.hibernate.type.AssociationType;
+import org.hibernate.type.ComponentType;
 import org.hibernate.type.CompositeType;
 import org.hibernate.type.Type;
 import org.hibernate.type.VersionType;
@@ -138,48 +140,56 @@ public final class PropertyFactory {
 		//		see org.hibernate.metamodel.spi.domain.AbstractAttributeContainer.locateOrCreateVirtualAttribute()
 
 		final String mappedUnsavedValue = mappedEntity.getHierarchyDetails().getEntityIdentifier().getUnsavedValue();
-		final Type type;
+
-		if ( mappedEntity.getHierarchyDetails().getEntityIdentifier().isIdentifierMapper() ) {
+		if ( mappedEntity.getHierarchyDetails().getEntityIdentifier().getNature()
-			type = sessionFactory.getTypeResolver().getTypeFactory().component(
+				== EntityIdentifierNature.NON_AGGREGATED_COMPOSITE ) {
+			// the "attribute" will need to be virtual since there is no single
+			// attribute identifying the identifier
+			final ComponentType type = sessionFactory.getTypeResolver().getTypeFactory().component(
 					new ComponentMetamodel(
 							sessionFactory.getServiceRegistry(),
 							( (EmbeddedAttributeBinding) attributeBinding ).getEmbeddableBinding(),
 							true,
-							true
+							mappedEntity.getHierarchyDetails().getEntityIdentifier().getLookupClassBinding().definedIdClass()
 					)
 			);
-		}
-		else {
-			type = attributeBinding.getHibernateTypeDescriptor().getResolvedTypeMapping();
-		}
 
-		IdentifierValue unsavedValue = UnsavedValueFactory.getUnsavedIdentifierValue(
+			final IdentifierValue unsavedValue = UnsavedValueFactory.getUnsavedIdentifierValue(
-				mappedUnsavedValue,
+					mappedUnsavedValue,
-				getGetter( attributeBinding, sessionFactory ),
+					getGetter( attributeBinding, sessionFactory ),
-				type,
+					type,
-				getConstructor(
+					getConstructor(
-						mappedEntity,
+							mappedEntity,
-						sessionFactory.getServiceRegistry().getService( ClassLoaderService.class )
+							sessionFactory.getServiceRegistry().getService( ClassLoaderService.class )
-				)
+					)
-		);
+			);
 
-		if ( attributeBinding.getAttribute().isSynthetic()  ) {
-			// this is a virtual id property...
 			return new IdentifierProperty(
 					type,
-					mappedEntity.getHierarchyDetails().getEntityIdentifier().isNonAggregatedComposite() &&
+					true,
-							mappedEntity.getHierarchyDetails().getEntityIdentifier().getIdClassClass() == null,
+					mappedEntity.getHierarchyDetails().getEntityIdentifier().getLookupClassBinding().definedIdClass(),
-					mappedEntity.getHierarchyDetails().getEntityIdentifier().isIdentifierMapper(),
 					unsavedValue,
 					generator
 			);
 		}
 		else {
+			final Type type = attributeBinding.getHibernateTypeDescriptor().getResolvedTypeMapping();
+
+			final IdentifierValue unsavedValue = UnsavedValueFactory.getUnsavedIdentifierValue(
+					mappedUnsavedValue,
+					getGetter( attributeBinding, sessionFactory ),
+					type,
+					getConstructor(
+							mappedEntity,
+							sessionFactory.getServiceRegistry().getService( ClassLoaderService.class )
+					)
+			);
+
 			return new IdentifierProperty(
 					attributeBinding.getAttribute().getName(),
 					null,
 					type,
-					mappedEntity.getHierarchyDetails().getEntityIdentifier().isNonAggregatedComposite(),
+					false,
 					unsavedValue,
 					generator
 			);

hibernate-core/src/main/java/org/hibernate/tuple/entity/AbstractEntityTuplizer.java

@@ -46,8 +46,6 @@ import org.hibernate.id.Assigned;
 import org.hibernate.internal.CoreLogging;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.loader.PropertyPath;
-import org.hibernate.mapping.PersistentClass;
-import org.hibernate.mapping.Property;
 import org.hibernate.metamodel.spi.binding.AttributeBinding;
 import org.hibernate.metamodel.spi.binding.EntityBinding;
 import org.hibernate.metamodel.spi.binding.EntityIdentifier;
@@ -238,7 +236,10 @@ public abstract class AbstractEntityTuplizer implements EntityTuplizer {
 	@Override
 	public Serializable getIdentifier(Object entity, SessionImplementor session) {
 		final Object id;
-		if ( entityMetamodel.getIdentifierProperty().isEmbedded() ) {
+		if ( identifierMapperType != null ) {
+			id = mappedIdentifierValueMarshaller.getIdentifier( entity, getEntityMode(), session );
+		}
+		else if ( entityMetamodel.getIdentifierProperty().isEmbedded() ) {
 			id = entity;
 		}
 		else if ( HibernateProxy.class.isInstance( entity ) ) {
@@ -246,12 +247,7 @@ public abstract class AbstractEntityTuplizer implements EntityTuplizer {
 		}
 		else {
 			if ( idGetter == null ) {
-				if (identifierMapperType==null) {
+				throw new HibernateException( "The class has no identifier property: " + getEntityName() );
-					throw new HibernateException( "The class has no identifier property: " + getEntityName() );
-				}
-				else {
-					id = mappedIdentifierValueMarshaller.getIdentifier( entity, getEntityMode(), session );
-				}
 			}
 			else {
                 id = idGetter.get( entity );
@@ -282,7 +278,10 @@ public abstract class AbstractEntityTuplizer implements EntityTuplizer {
 
 	@Override
 	public void setIdentifier(Object entity, Serializable id, SessionImplementor session) {
-		if ( entityMetamodel.getIdentifierProperty().isEmbedded() ) {
+		if ( identifierMapperType != null && identifierMapperType.getReturnedClass().isInstance( id ) ) {
+			mappedIdentifierValueMarshaller.setIdentifier( entity, id, getEntityMode(), session );
+		}
+		else if ( entityMetamodel.getIdentifierProperty().isEmbedded() ) {
 			if ( entity != id ) {
 				CompositeType copier = (CompositeType) entityMetamodel.getIdentifierProperty().getType();
 				copier.setPropertyValues( entity, copier.getPropertyValues( id, getEntityMode() ), getEntityMode() );
@@ -291,8 +290,11 @@ public abstract class AbstractEntityTuplizer implements EntityTuplizer {
 		else if ( idSetter != null ) {
 			idSetter.set( entity, id, getFactory() );
 		}
-		else if ( identifierMapperType != null ) {
+		else {
-			mappedIdentifierValueMarshaller.setIdentifier( entity, id, getEntityMode(), session );
+			throw new IllegalArgumentException(
+					"Could not determine how to set given value [" + id
+							+ "] as identifier value for entity [" + getEntityName() + "]"
+			);
 		}
 	}
 

hibernate-core/src/test/java/org/hibernate/metamodel/spi/binding/BindingHelper.java

@@ -0,0 +1,55 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2014, Red Hat Inc. or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Inc.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.metamodel.spi.binding;
+
+import static org.hibernate.testing.junit4.ExtraAssertions.assertTyping;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author Steve Ebersole
+ */
+public class BindingHelper {
+	/**
+	 * Help to get an attribute binding that we are fully expecting to exist.
+	 * <p/>
+	 * Helpful because it validates that the attribute exists and manages checking the
+	 * specific type and casting.
+	 *
+	 * @param attributeContainer The container for the attribute
+	 * @param attributeName The name of the attribute to get
+	 * @param expectedType The specific AttributeBinding sub-type we are expecting
+	 * @param <T> The generic representation of `expectedType`
+	 *
+	 * @return The typed attribute binding
+	 */
+	public static <T extends AttributeBinding> T locateAttributeBinding(
+			AttributeBindingContainer attributeContainer,
+			String attributeName,
+			Class<T> expectedType) {
+		AttributeBinding attributeBinding = attributeContainer.locateAttributeBinding( attributeName );
+		assertNotNull( "Could not locate attribute named " + attributeName, attributeBinding );
+		return assertTyping( expectedType, attributeBinding );
+
+	}
+}

hibernate-core/src/test/java/org/hibernate/metamodel/spi/binding/cid/BasicEmbeddedIdTest.java

@@ -23,33 +23,40 @@
  */
 package org.hibernate.metamodel.spi.binding.cid;
 
+import javax.persistence.Column;
 import javax.persistence.Embeddable;
 import javax.persistence.EmbeddedId;
 import javax.persistence.Entity;
 
 import org.hibernate.id.EntityIdentifierNature;
-import org.hibernate.metamodel.spi.binding.AttributeBinding;
-import org.hibernate.metamodel.spi.binding.AttributeBindingContainer;
 import org.hibernate.metamodel.spi.binding.BasicAttributeBinding;
 import org.hibernate.metamodel.spi.binding.EmbeddedAttributeBinding;
 import org.hibernate.metamodel.spi.binding.EntityBinding;
+import org.hibernate.metamodel.spi.binding.RelationalValueBinding;
 import org.hibernate.metamodel.spi.binding.SingularAttributeBinding;
 
 import org.hibernate.testing.junit4.BaseAnnotationBindingTestCase;
 import org.hibernate.testing.junit4.Resources;
 import org.junit.Test;
 
+import static org.hibernate.metamodel.spi.binding.BindingHelper.locateAttributeBinding;
 import static org.hibernate.testing.junit4.ExtraAssertions.assertTyping;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 
 /**
+ * Assertions about the metamodel interpretations of basic {@link javax.persistence.EmbeddedId} usage.
+ *
  * @author Steve Ebersole
+ *
+ * @see org.hibernate.metamodel.spi.binding.cid.BasicIdClassTest
  */
 public class BasicEmbeddedIdTest extends BaseAnnotationBindingTestCase {
 	@Embeddable
 	public static class CoursePK {
+		@Column( name = "dept" )
 		public String department;
 		public String code;
 	}
@@ -64,30 +71,61 @@ public class BasicEmbeddedIdTest extends BaseAnnotationBindingTestCase {
 	@Test
 	@Resources( annotatedClasses = {CoursePK.class, Course.class} )
 	public void testBasicUsage() {
+		// get the Course entity binding
 		EntityBinding courseBinding = getEntityBinding( Course.class );
-		assertEquals( 2, courseBinding.getAttributeBindingClosureSpan() );
+		assertNotNull( courseBinding );
-
-		EmbeddedAttributeBinding keyBinding = locateAttributeBinding( courseBinding, "key", EmbeddedAttributeBinding.class );
-		assertEquals( 2, keyBinding.getEmbeddableBinding().attributeBindingSpan() );
-
 		assertEquals(
 				EntityIdentifierNature.AGGREGATED_COMPOSITE,
 				courseBinding.getHierarchyDetails().getEntityIdentifier().getNature()
 		);
+		assertNull(
+				courseBinding.getHierarchyDetails().getEntityIdentifier().getLookupClassBinding().getIdClassType()
+		);
+
+		// Course should be interpreted as defining 2 attributes: `key` and `title`
+		assertEquals( 2, courseBinding.getAttributeBindingClosureSpan() );
+
+		// just make sure `title` is one of them
+		locateAttributeBinding( courseBinding, "title", BasicAttributeBinding.class );
+
+		// locate the attribute binding for `key` which is the EmbeddedId attribute
+		EmbeddedAttributeBinding keyBinding = locateAttributeBinding(
+				courseBinding,
+				"key",
+				EmbeddedAttributeBinding.class
+		);
 		SingularAttributeBinding identifierAttribute =  courseBinding.getHierarchyDetails().getEntityIdentifier().getAttributeBinding();
-		// NOTE : same does '=='
+		// NOTE : assertSame() does '=='
 		assertSame( keyBinding, identifierAttribute );
 
-		BasicAttributeBinding titleBinding = locateAttributeBinding( courseBinding, "title", BasicAttributeBinding.class );
+		// the Embeddable for `key` (CoursePK) should also define 2 attributes: `department` and `code`
-	}
+		assertEquals( 2, keyBinding.getEmbeddableBinding().attributeBindingSpan() );
 
-	private <T extends AttributeBinding> T locateAttributeBinding(
+		BasicAttributeBinding deptAttribute = locateAttributeBinding(
-			AttributeBindingContainer attributeContainer,
+				keyBinding.getEmbeddableBinding(),
-			String attributeName,
+				"department",
-			Class<T> expectedType) {
+				BasicAttributeBinding.class
-		AttributeBinding attributeBinding = attributeContainer.locateAttributeBinding( attributeName );
+		);
-		assertNotNull( "Could not locate attribute named " + attributeName, attributeBinding );
+		assertEquals( 1, deptAttribute.getRelationalValueBindings().size() );
-		return assertTyping( expectedType, attributeBinding );
+		RelationalValueBinding deptColumnBinding = deptAttribute.getRelationalValueBindings().get( 0 );
+		org.hibernate.metamodel.spi.relational.Column deptColumn = assertTyping(
+				org.hibernate.metamodel.spi.relational.Column.class,
+				deptColumnBinding.getValue()
+		);
+		assertEquals( "dept", deptColumn.getColumnName().getText() );
+
+		BasicAttributeBinding codeAttribute = locateAttributeBinding(
+				keyBinding.getEmbeddableBinding(),
+				"code",
+				BasicAttributeBinding.class
+		);
+		assertEquals( 1, codeAttribute.getRelationalValueBindings().size() );
+		RelationalValueBinding codeColumnBinding = codeAttribute.getRelationalValueBindings().get( 0 );
+		org.hibernate.metamodel.spi.relational.Column codeColumn = assertTyping(
+				org.hibernate.metamodel.spi.relational.Column.class,
+				codeColumnBinding.getValue()
+		);
+		assertEquals( "code", codeColumn.getColumnName().getText() );
 
 	}
 

hibernate-core/src/test/java/org/hibernate/metamodel/spi/binding/cid/BasicIdClassTest.java

@@ -0,0 +1,150 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2014, Red Hat Inc. or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Inc.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.metamodel.spi.binding.cid;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.IdClass;
+
+import org.hibernate.id.EntityIdentifierNature;
+import org.hibernate.metamodel.spi.binding.AttributeBinding;
+import org.hibernate.metamodel.spi.binding.BasicAttributeBinding;
+import org.hibernate.metamodel.spi.binding.EmbeddableBinding;
+import org.hibernate.metamodel.spi.binding.EmbeddedAttributeBinding;
+import org.hibernate.metamodel.spi.binding.EntityBinding;
+import org.hibernate.metamodel.spi.binding.RelationalValueBinding;
+
+import org.hibernate.testing.junit4.BaseAnnotationBindingTestCase;
+import org.hibernate.testing.junit4.Resources;
+import org.junit.Test;
+
+import static org.hibernate.metamodel.spi.binding.BindingHelper.locateAttributeBinding;
+import static org.hibernate.testing.junit4.ExtraAssertions.assertTyping;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Assertions about the metamodel interpretations of basic {@link javax.persistence.IdClass} usage.
+ *
+ * @author Steve Ebersole
+ *
+ * @see org.hibernate.metamodel.spi.binding.cid.BasicEmbeddedIdTest
+ */
+public class BasicIdClassTest extends BaseAnnotationBindingTestCase {
+	public static class CoursePK {
+		public String department;
+		public String code;
+	}
+
+	@Entity
+	@IdClass( CoursePK.class )
+	public static class Course {
+		@Id
+		@Column( name = "dept" )
+		public String department;
+		@Id
+		public String code;
+		private String title;
+	}
+
+	@Test
+	@Resources( annotatedClasses = Course.class )
+	public void testBasicUsage() {
+		// get the Course entity binding
+		EntityBinding courseBinding = getEntityBinding( Course.class );
+		assertNotNull( courseBinding );
+		assertEquals(
+				EntityIdentifierNature.NON_AGGREGATED_COMPOSITE,
+				courseBinding.getHierarchyDetails().getEntityIdentifier().getNature()
+		);
+		Class idClassClass = courseBinding.getHierarchyDetails().getEntityIdentifier()
+				.getLookupClassBinding()
+				.getIdClassType();
+		assertNotNull( idClassClass );
+
+		// Course should be interpreted as defining 3 attributes: `department`, `code` and `title`
+		assertEquals( 3, courseBinding.getAttributeBindingClosureSpan() );
+
+		// just make sure `title` is one of them
+		locateAttributeBinding( courseBinding, "title", BasicAttributeBinding.class );
+
+		BasicAttributeBinding deptAttribute = locateAttributeBinding(
+				courseBinding,
+				"department",
+				BasicAttributeBinding.class
+		);
+		assertEquals( 1, deptAttribute.getRelationalValueBindings().size() );
+		RelationalValueBinding deptColumnBinding = deptAttribute.getRelationalValueBindings().get( 0 );
+		org.hibernate.metamodel.spi.relational.Column deptColumn = assertTyping(
+				org.hibernate.metamodel.spi.relational.Column.class,
+				deptColumnBinding.getValue()
+		);
+		assertEquals( "dept", deptColumn.getColumnName().getText() );
+
+		BasicAttributeBinding codeAttribute = locateAttributeBinding(
+				courseBinding,
+				"code",
+				BasicAttributeBinding.class
+		);
+		RelationalValueBinding codeColumnBinding = codeAttribute.getRelationalValueBindings().get( 0 );
+		org.hibernate.metamodel.spi.relational.Column codeColumn = assertTyping(
+				org.hibernate.metamodel.spi.relational.Column.class,
+				codeColumnBinding.getValue()
+		);
+		assertEquals( "code", codeColumn.getColumnName().getText() );
+
+
+		assertTrue(
+				courseBinding.getHierarchyDetails().getEntityIdentifier().isIdentifierAttributeBinding(
+						deptAttribute
+				)
+		);
+
+		assertTrue(
+				courseBinding.getHierarchyDetails().getEntityIdentifier().isIdentifierAttributeBinding(
+						codeAttribute
+				)
+		);
+
+		// get the virtual (non-aggregated composite) id attribute
+		EmbeddedAttributeBinding identifierAttribute = (EmbeddedAttributeBinding) courseBinding.getHierarchyDetails()
+				.getEntityIdentifier()
+				.getAttributeBinding();
+		assertNotNull( identifierAttribute );
+		// NOTE : assertSame() does `==`
+
+		EmbeddableBinding virtualEmbeddable = identifierAttribute.getEmbeddableBinding();
+		assertEquals( 2, virtualEmbeddable.attributeBindingSpan() );
+
+		for ( AttributeBinding subAttributeBinding : virtualEmbeddable.attributeBindings() ) {
+			assertTrue(
+					subAttributeBinding == deptAttribute
+							|| subAttributeBinding == codeAttribute
+			);
+		}
+
+	}
+}