HHH-7124 : Bind many-to-one foreign key

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

@@ -353,6 +353,7 @@ private void bindCollectionKey(
 				StringHelper.isEmpty( keySource.getExplicitForeignKeyName() )
 						? null
 						: quotedIdentifier( keySource.getExplicitForeignKeyName() );
+		// TODO: deal with secondary tables...
 		final TableSpecification table = attributeBinding.getContainer().seekEntityBinding().getPrimaryTable();
 		keyBinding.prepareForeignKey( foreignKeyName, collectionTable, table );
 		keyBinding.getForeignKey().setDeleteRule( keySource.getOnDeleteAction() );
@@ -506,6 +507,110 @@ private CompositeAttributeBinding bindComponentAttribute(
 		return attributeBinding;
 	}
 
+	private ForeignKey createOrLocateForeignKey(
+			String foreignKeyName,
+			SingularAttributeBinding sourceAttributeBinding,
+			SingularAttributeBinding targetAttributeBinding) {
+		if ( sourceAttributeBinding.getRelationalValueBindings().isEmpty() ) {
+			throw new MappingException( 
+					String.format(
+							"Cannot create foreign key for attribute (%s) because it has no columns/derived values configured.",
+							sourceAttributeBinding.getAttribute().getName()
+					),
+					bindingContexts.peek().getOrigin() 
+			);
+		}
+		if ( targetAttributeBinding.getRelationalValueBindings().isEmpty() ) {
+			throw new MappingException(
+					String.format(
+							"Cannot create foreign key for attribute (%s) because the target attribute (%s) has no columns/derived values configured.",
+							sourceAttributeBinding.getAttribute().getName(),
+							targetAttributeBinding.getAttribute().getName()
+					),
+					bindingContexts.peek().getOrigin()
+			);
+		}
+		// TODO: deal with secondary tables
+		// for now just use the the EntityBinding primary table.
+		return createOrLocateForeignKey(
+				foreignKeyName,
+				sourceAttributeBinding.getContainer().seekEntityBinding().getPrimaryTable(),
+				targetAttributeBinding.getContainer().seekEntityBinding().getPrimaryTable()
+		);
+	}
+
+	private ForeignKey createOrLocateForeignKey(
+			String foreignKeyName,
+			TableSpecification sourceTable,
+			TableSpecification targetTable) {
+		ForeignKey foreignKey = null;
+		if ( foreignKeyName == null ) {
+			// todo: for now lets assume we have to create it, but eventually we should look through the
+			// candidate foreign keys referencing targetTable also...
+			foreignKey = sourceTable.createForeignKey( targetTable, null );
+		} else {
+			foreignKey = sourceTable.locateForeignKey( foreignKeyName );
+			if ( foreignKey == null ) {
+				foreignKey = sourceTable.createForeignKey( targetTable, foreignKeyName );
+			}
+		}
+		return foreignKey;
+	}
+
+	private void bindForeignKeyColumns(
+			ForeignKey foreignKey,
+			SingularAttributeBinding sourceAttributeBinding,
+			SingularAttributeBinding targetAttributeBinding) {
+		final List<RelationalValueBinding> sourceValues = sourceAttributeBinding.getRelationalValueBindings();
+		final List<RelationalValueBinding> targetValues = targetAttributeBinding.getRelationalValueBindings();
+		if ( sourceValues.size() != targetValues.size() ) {
+			throw new MappingException(
+					String.format(
+							"Cannot create foreign key because number of columns in source attribute (%s) is not the same as the number of columns in the target attribute (%s).",
+							sourceAttributeBinding.getAttribute().getName(),
+							targetAttributeBinding.getAttribute().getName()
+					),
+					bindingContexts.peek().getOrigin()
+			);
+		}
+		for ( int i = 0 ; i < sourceValues.size() ; i++ ) {
+			final Value sourceValue = sourceValues.get( i ).getValue();
+			final Value targetValue = targetValues.get( i ).getValue();
+			if ( Column.class.isInstance( sourceValue ) ) {
+				Column sourceColumn = Column.class.cast( sourceValue );
+				if ( !Column.class.isInstance( targetValue ) ) {
+					throw new MappingException( 
+							String.format( 
+									"Cannot create foreign key for (%s) because the source value is a column (%s) and the corresponding value in the target attribute (%s) is a derived value",
+									sourceAttributeBinding.getAttribute().getName(),
+									sourceColumn.getColumnName(),
+									targetAttributeBinding.getAttribute().getName()
+							),							
+							bindingContexts.peek().getOrigin()
+					);
+				}
+				foreignKey.addColumnMapping( Column.class.cast( sourceValue ), Column.class.cast( targetValue ) );
+			}
+			else {
+				if ( Column.class.isInstance( targetValue ) ) {
+					Column targetColumn = Column.class.cast( targetValue );
+					throw new MappingException(
+							String.format(
+									"Cannot create foreign key for (%s) because the source value is a derived value and the corresponding value in the target attribute (%s) is a column (%s).",
+									sourceAttributeBinding.getAttribute().getName(),
+									targetAttributeBinding.getAttribute().getName(),
+									targetColumn.getColumnName()
+							),
+							bindingContexts.peek().getOrigin()
+					);
+				}
+				throw new NotYetImplementedException(
+						"Derived values are not supported when creating a foreign key that targets attribute columns."
+				);
+			}
+		}
+	}
+	
 	private void bindDiscriminator( final EntityBinding rootEntityBinding, final RootEntitySource rootEntitySource ) {
 		final DiscriminatorSource discriminatorSource = rootEntitySource.getDiscriminatorSource();
 		if ( discriminatorSource == null ) {
@@ -714,12 +819,14 @@ private ManyToOneAttributeBinding bindManyToOneAttribute(
 			attribute = createSingularAttribute( attributeBindingContainer, attributeSource );
 		}
 		// TODO: figure out which table is used (could be secondary table...)
+		TableSpecification table = attributeBindingContainer.seekEntityBinding().getPrimaryTable();
 		final List< RelationalValueBinding > relationalValueBindings =
 				bindValues(
 						attributeBindingContainer,
 						attributeSource,
 						attribute,
-						attributeBindingContainer.seekEntityBinding().getPrimaryTable() );
+						table
+				);
 		org.hibernate.internal.util.Value< Class< ? >> referencedJavaTypeValue = createSingularAttributeJavaType( attribute );
 		final String referencedEntityName =
 				attributeSource.getReferencedEntityName() != null
@@ -730,6 +837,17 @@ private ManyToOneAttributeBinding bindManyToOneAttribute(
 				attributeSource.getReferencedEntityAttributeName() == null
 						? referencedEntityBinding.getHierarchyDetails().getEntityIdentifier().getValueBinding()
 						: referencedEntityBinding.locateAttributeBinding( attributeSource.getReferencedEntityAttributeName() );
+		if ( ! referencedAttributeBinding.getAttribute().isSingular() ) {
+			throw new MappingException(
+					String.format( "Many-to-one attribute (%s) references a plural attribute (%s)",
+							attribute.getName(),
+							referencedAttributeBinding.getAttribute().getName()
+					),
+					bindingContexts.peek().getOrigin()
+			);
+		}
+		final SingularAttributeBinding singularReferencedAttributeBinding =
+				(SingularAttributeBinding) referencedAttributeBinding;
 		// todo : we should consider basing references on columns instead of property-ref, which would require a resolution (later) of property-ref to column names
 		final ManyToOneAttributeBinding attributeBinding =
 				attributeBindingContainer.makeManyToOneAttributeBinding(
@@ -738,10 +856,18 @@ private ManyToOneAttributeBinding bindManyToOneAttribute(
 						attributeSource.isIncludedInOptimisticLocking(),
 						attributeSource.isLazy(),
 						createMetaAttributeContext( attributeBindingContainer, attributeSource ),
-						referencedAttributeBinding,
+						singularReferencedAttributeBinding,
 						relationalValueBindings );
 		// TODO: is this needed?
 		referencedAttributeBinding.addEntityReferencingAttributeBinding( attributeBinding );
+		// Foreign key...
+		ForeignKey foreignKey = createOrLocateForeignKey(
+				attributeSource.getForeignKeyName(),
+				attributeBinding,
+				singularReferencedAttributeBinding
+		);
+		bindForeignKeyColumns( foreignKey, attributeBinding, singularReferencedAttributeBinding );
+		// Type resolution...
 		if ( !attribute.isTypeResolved() ) {
 			attribute.resolveType( referencedEntityBinding.getEntity() );
 		}
@@ -846,17 +972,9 @@ private void bindSecondaryTables( final EntityBinding entityBinding, final Entit
 			final TableSpecification table = createTable( secondaryTableSource.getTableSource(), null );
 			// todo: really need a concept like SecondaryTableSource in the binding model as well
 			// so that EntityBinding can know the proper foreign key to use to build SQL statements.
-			ForeignKey foreignKey = null;
-			if ( secondaryTableSource.getForeignKeyName() == null ) {
-				// todo: for now lets assume we have to create it, but eventually we should look through the
-				// candidate foreign keys referencing primary table also...
-				foreignKey = table.createForeignKey( primaryTable, null );
-			} else {
-				foreignKey = table.locateForeignKey( secondaryTableSource.getForeignKeyName() );
-				if ( foreignKey == null ) {
-					foreignKey = table.createForeignKey( primaryTable, secondaryTableSource.getForeignKeyName() );
-				}
-			}
+			ForeignKey foreignKey = createOrLocateForeignKey(
+					secondaryTableSource.getForeignKeyName(), table, primaryTable
+			);
 			for ( final PrimaryKeyJoinColumnSource joinColumnSource : secondaryTableSource.getJoinColumns() ) {
 				// todo : currently we only support columns here, not formulas
 				// todo : apply naming strategy to infer missing column name

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

@@ -115,7 +115,7 @@ public ManyToOneAttributeBinding makeManyToOneAttributeBinding(
 			boolean includedInOptimisticLocking,
 			boolean lazy,
 			MetaAttributeContext metaAttributeContext,
-			AttributeBinding referencedAttributeBinding,
+			SingularAttributeBinding referencedAttributeBinding,
 			List<RelationalValueBinding> valueBindings);
 
 	/**

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

@@ -185,7 +185,7 @@ public ManyToOneAttributeBinding makeManyToOneAttributeBinding(
 			boolean includedInOptimisticLocking,
 			boolean lazy,
 			MetaAttributeContext metaAttributeContext,
-			AttributeBinding referencedAttributeBinding,
+			SingularAttributeBinding referencedAttributeBinding,
 			List<RelationalValueBinding> valueBindings) {
 		final ManyToOneAttributeBinding binding = new ManyToOneAttributeBinding(
 				this,

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

@@ -531,7 +531,7 @@ public ManyToOneAttributeBinding makeManyToOneAttributeBinding(
 			boolean includedInOptimisticLocking,
 			boolean lazy,
 			MetaAttributeContext metaAttributeContext,
-			AttributeBinding referencedAttributeBinding,
+			SingularAttributeBinding referencedAttributeBinding,
 			List<RelationalValueBinding> valueBindings) {
 		final ManyToOneAttributeBinding binding = new ManyToOneAttributeBinding(
 				this,

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

@@ -47,7 +47,7 @@ public class ManyToOneAttributeBinding
 
 	private final List<RelationalValueBinding> relationalValueBindings;
 
-	private final AttributeBinding referencedAttributeBinding;
+	private final SingularAttributeBinding referencedAttributeBinding;
 
 	private boolean isLogicalOneToOne;
 
@@ -62,7 +62,7 @@ public ManyToOneAttributeBinding(
 			boolean includedInOptimisticLocking,
 			boolean lazy,
 			MetaAttributeContext metaAttributeContext,
-			AttributeBinding referencedAttributeBinding,
+			SingularAttributeBinding referencedAttributeBinding,
 			List<RelationalValueBinding> relationalValueBindings) {
 		super(
 				container,
@@ -196,38 +196,6 @@ public final EntityBinding getReferencedEntityBinding() {
 		return (EntityBinding) referencedAttributeBinding.getContainer();
 	}
 
-//	private void buildForeignKey() {
-//		// TODO: move this stuff to relational model
-//		ForeignKey foreignKey = getValue().getTable()
-//				.createForeignKey( referencedAttributeBinding.getValue().getTable(), foreignKeyName );
-//		Iterator<SimpleValue> referencingValueIterator = getSimpleValues().iterator();
-//		Iterator<SimpleValue> targetValueIterator = referencedAttributeBinding.getSimpleValues().iterator();
-//		while ( referencingValueIterator.hasNext() ) {
-//			if ( !targetValueIterator.hasNext() ) {
-//				// TODO: improve this message
-//				throw new MappingException(
-//						"number of values in many-to-one reference is greater than number of values in target"
-//				);
-//			}
-//			SimpleValue referencingValue = referencingValueIterator.next();
-//			SimpleValue targetValue = targetValueIterator.next();
-//			if ( Column.class.isInstance( referencingValue ) ) {
-//				if ( !Column.class.isInstance( targetValue ) ) {
-//					// TODO improve this message
-//					throw new MappingException( "referencing value is a column, but target is not a column" );
-//				}
-//				foreignKey.addColumnMapping( Column.class.cast( referencingValue ), Column.class.cast( targetValue ) );
-//			}
-//			else if ( Column.class.isInstance( targetValue ) ) {
-//				// TODO: improve this message
-//				throw new MappingException( "referencing value is not a column, but target is a column." );
-//			}
-//		}
-//		if ( targetValueIterator.hasNext() ) {
-//			throw new MappingException( "target value has more simple values than referencing value" );
-//		}
-//	}
-//
 //	public void validate() {
 //		// can't check this until both the domain and relational states are initialized...
 //		if ( getCascadeTypes().contains( CascadeType.DELETE_ORPHAN ) ) {

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

@@ -24,6 +24,7 @@
 package org.hibernate.metamodel.spi.binding;
 
 import java.sql.Types;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
@@ -42,8 +43,10 @@
 import org.hibernate.metamodel.spi.domain.SingularAttribute;
 import org.hibernate.metamodel.internal.MetadataImpl;
 import org.hibernate.metamodel.spi.relational.Column;
+import org.hibernate.metamodel.spi.relational.ForeignKey;
 import org.hibernate.metamodel.spi.relational.Identifier;
 import org.hibernate.metamodel.spi.relational.JdbcDataType;
+import org.hibernate.metamodel.spi.relational.TableSpecification;
 import org.hibernate.metamodel.spi.relational.Value;
 import org.hibernate.metamodel.spi.source.MetadataImplementor;
 import org.hibernate.service.ServiceRegistry;
@@ -133,7 +136,9 @@ public void testEntityWithManyToOneMapping() {
 				metadata,
 				entityWithManyToOneBinding,
 				attributeBinding,
-				simpleEntityBinding.getHierarchyDetails().getEntityIdentifier().getValueBinding(),
+				SingularAttributeBinding.class.cast( 
+						simpleEntityBinding.getHierarchyDetails().getEntityIdentifier().getValueBinding()
+				),
 				"`simpleEntity`"
 		);
 
@@ -141,7 +146,7 @@ public void testEntityWithManyToOneMapping() {
 				metadata,
 				entityWithManyToOneBinding,
 				entityWithManyToOneBinding.locateAttributeBinding( "simpleEntityFromPropertyRef" ),
-				simpleEntityBinding.locateAttributeBinding( "name" ),
+				SingularAttributeBinding.class.cast( simpleEntityBinding.locateAttributeBinding( "name" ) ),
 				"`simplename`"
 		);
 	}
@@ -150,7 +155,7 @@ private void checkManyToOneAttributeBinding(
 			MetadataImplementor metadata,
 			EntityBinding entityWithManyToOneBinding,
 			AttributeBinding attributeBinding, 
-			AttributeBinding referencedAttributeBinding,
+			SingularAttributeBinding referencedAttributeBinding,
 			String manyToOneColumnName) {
 		final EntityBinding referencedEntityBinding = referencedAttributeBinding.getContainer().seekEntityBinding();
 		final String referencedEntityName = referencedEntityBinding.getEntity().getName();
@@ -223,6 +228,25 @@ private void checkManyToOneAttributeBinding(
 		assertEquals( referencedJdbcDataType.getTypeCode(), jdbcDataType.getTypeCode() );
 		assertEquals( referencedJdbcDataType.getJavaType(), jdbcDataType.getJavaType() );
 		assertEquals( referencedJdbcDataType.getTypeName(), jdbcDataType.getTypeName() );
+		
+		// locate the foreignKey
+		boolean sourceColumnFound = false;
+		for ( ForeignKey fk : column.getTable().getForeignKeys() ) {
+			for ( Column sourceColumn : fk.getSourceColumns() ) {
+				if ( sourceColumn == column ) {
+					assertFalse( "source column not found in more than one foreign key", sourceColumnFound );
+					sourceColumnFound = true;
+					Iterator<Column> targetColumnIterator = fk.getTargetColumns().iterator();
+					assertTrue( targetColumnIterator.hasNext() );
+					assertSame( 
+							referencedAttributeBinding.getRelationalValueBindings().iterator().next().getValue(),
+							targetColumnIterator.next()							
+					);
+					assertFalse( targetColumnIterator.hasNext() );					
+				}
+			}
+		}
+		assertTrue( "foreign key with specified source column found", sourceColumnFound );
 	}
 
 	@Test