unify new ValueGenerationStrategy interfaces with existing ValueGeneration stuff

- introduce ValueGenerationStrategy to abstract over IMVGS and IDVGS
- make ValueGeneration a mixin of IMVGS with IDVGS
- make IDVGS accept a Dialect for SQL fragment generation
  (it was based on an obsolete version of ValueGeneration)
- adapt all the code which only handled single-column value generation
  to handle multiple columns, as introduced by IDVGS

Still to do: the whole AnnotationValueGeneration stuff still requires the use
of the mixin interface, and you can't use IMVGS or IDVGS directly. That bit is
going to require a bit more thinking about backward compatibility.

hibernate-core/src/main/java/org/hibernate/cfg/annotations/PropertyBinder.java

@@ -40,8 +40,10 @@ import org.hibernate.mapping.ToOne;
 import org.hibernate.mapping.Value;
 import org.hibernate.metamodel.spi.EmbeddableInstantiator;
 import org.hibernate.property.access.spi.PropertyAccessStrategy;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.tuple.AnnotationValueGeneration;
 import org.hibernate.tuple.AttributeBinder;
+import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 import org.hibernate.tuple.GenerationTiming;
 import org.hibernate.tuple.ValueGeneration;
 import org.hibernate.tuple.ValueGenerator;
@@ -383,19 +385,17 @@ public class PropertyBinder {
 		}
 	}
 
-	private ValueGeneration determineValueGenerationStrategy(XProperty property) {
+	private ValueGenerationStrategy determineValueGenerationStrategy(XProperty property) {
-		ValueGeneration valueGeneration = getValueGenerationFromAnnotations( property );
+		ValueGenerationStrategy valueGeneration = getValueGenerationFromAnnotations( property );
-
 		if ( valueGeneration == null ) {
 			return NoValueGeneration.INSTANCE;
 		}
-
+		if ( valueGeneration instanceof InDatabaseValueGenerationStrategy) {
-		if ( !valueGeneration.writePropertyValue() ) {
 			// if we have an in-db generator, mark it as not insertable nor updatable
-			insertable = false;
+			final boolean writable = ( (InDatabaseValueGenerationStrategy) valueGeneration ).writePropertyValue();
-			updatable = false;
+			insertable = writable;
+			updatable = writable;
 		}
-
 		return valueGeneration;
 	}
 

hibernate-core/src/main/java/org/hibernate/mapping/Property.java

@@ -27,7 +27,7 @@ import org.hibernate.property.access.spi.PropertyAccessStrategy;
 import org.hibernate.property.access.spi.PropertyAccessStrategyResolver;
 import org.hibernate.property.access.spi.Setter;
 import org.hibernate.service.ServiceRegistry;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.type.CompositeType;
 import org.hibernate.type.Type;
 
@@ -45,7 +45,7 @@ public class Property implements Serializable, MetaAttributable {
 	private boolean insertable = true;
 	private boolean selectable = true;
 	private boolean optimisticLocked = true;
-	private ValueGeneration valueGenerationStrategy;
+	private ValueGenerationStrategy valueGenerationStrategy;
 	private String propertyAccessorName;
 	private PropertyAccessStrategy propertyAccessStrategy;
 	private boolean lazy;
@@ -216,11 +216,11 @@ public class Property implements Serializable, MetaAttributable {
 		return insertable && value.hasAnyInsertableColumns();
 	}
 
-	public ValueGeneration getValueGenerationStrategy() {
+	public ValueGenerationStrategy getValueGenerationStrategy() {
 		return valueGenerationStrategy;
 	}
 
-	public void setValueGenerationStrategy(ValueGeneration valueGenerationStrategy) {
+	public void setValueGenerationStrategy(ValueGenerationStrategy valueGenerationStrategy) {
 		this.valueGenerationStrategy = valueGenerationStrategy;
 	}
 

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

@@ -9,7 +9,7 @@ package org.hibernate.metamodel.mapping;
 import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.sql.results.graph.DatabaseSnapshotContributor;
 import org.hibernate.sql.results.graph.Fetchable;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.type.descriptor.java.JavaType;
 import org.hibernate.type.descriptor.java.MutabilityPlan;
 import org.hibernate.type.descriptor.java.MutabilityPlanExposer;
@@ -70,7 +70,7 @@ public interface AttributeMapping
 	 *
 	 * @apiNote Only relevant for non-id attributes
 	 */
-	ValueGeneration getValueGeneration();
+	ValueGenerationStrategy getValueGeneration();
 
 	@Override
 	default EntityMappingType findContainingEntityMapping() {

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

@@ -9,8 +9,9 @@ package org.hibernate.metamodel.mapping;
 import org.hibernate.Incubating;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.metamodel.mapping.internal.NoGeneratedValueResolver;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.tuple.GenerationTiming;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.InMemoryValueGenerationStrategy;
 
 /**
  * Generalized contract covering an attribute's generation handling
@@ -20,7 +21,7 @@ import org.hibernate.tuple.ValueGeneration;
 @Incubating
 public interface GeneratedValueResolver {
 	static GeneratedValueResolver from(
-			ValueGeneration valueGeneration,
+			ValueGenerationStrategy valueGeneration,
 			GenerationTiming requestedTiming,
 			int dbSelectionPosition) {
 		assert requestedTiming != GenerationTiming.NEVER;
@@ -38,7 +39,8 @@ public interface GeneratedValueResolver {
 			return new InDatabaseGeneratedValueResolver( requestedTiming, dbSelectionPosition );
 		}
 		else {
-			return new InMemoryGeneratedValueResolver( valueGeneration.getValueGenerator(), requestedTiming );
+			InMemoryValueGenerationStrategy generation = (InMemoryValueGenerationStrategy) valueGeneration;
+			return new InMemoryGeneratedValueResolver( generation.getValueGenerator(), requestedTiming );
 		}
 	}
 

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

@@ -13,7 +13,7 @@ import org.hibernate.metamodel.mapping.ManagedMappingType;
 import org.hibernate.metamodel.mapping.SingularAttributeMapping;
 import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.sql.results.graph.FetchOptions;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.ValueGenerationStrategy;
 
 /**
  * @author Steve Ebersole
@@ -23,7 +23,7 @@ public abstract class AbstractSingularAttributeMapping
 		implements SingularAttributeMapping {
 
 	private final PropertyAccess propertyAccess;
-	private final ValueGeneration valueGeneration;
+	private final ValueGenerationStrategy valueGeneration;
 
 	public AbstractSingularAttributeMapping(
 			String name,
@@ -32,7 +32,7 @@ public abstract class AbstractSingularAttributeMapping
 			FetchOptions mappedFetchOptions,
 			ManagedMappingType declaringType,
 			PropertyAccess propertyAccess,
-			ValueGeneration valueGeneration) {
+			ValueGenerationStrategy valueGeneration) {
 		super( name, attributeMetadataAccess, mappedFetchOptions, stateArrayPosition, declaringType );
 		this.propertyAccess = propertyAccess;
 		this.valueGeneration = valueGeneration != null
@@ -48,7 +48,7 @@ public abstract class AbstractSingularAttributeMapping
 			FetchStyle fetchStyle,
 			ManagedMappingType declaringType,
 			PropertyAccess propertyAccess,
-			ValueGeneration valueGeneration) {
+			ValueGenerationStrategy valueGeneration) {
 		super( name, attributeMetadataAccess, fetchTiming, fetchStyle, stateArrayPosition, declaringType );
 		this.propertyAccess = propertyAccess;
 		this.valueGeneration = valueGeneration != null
@@ -62,7 +62,7 @@ public abstract class AbstractSingularAttributeMapping
 	}
 
 	@Override
-	public ValueGeneration getValueGeneration() {
+	public ValueGenerationStrategy getValueGeneration() {
 		return valueGeneration;
 	}
 }

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

@@ -36,7 +36,7 @@ import org.hibernate.sql.results.graph.Fetch;
 import org.hibernate.sql.results.graph.FetchParent;
 import org.hibernate.sql.results.graph.basic.BasicFetch;
 import org.hibernate.sql.results.graph.basic.BasicResult;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.type.descriptor.java.JavaType;
 
 /**
@@ -87,7 +87,7 @@ public class BasicAttributeMapping
 			JdbcMapping jdbcMapping,
 			ManagedMappingType declaringType,
 			PropertyAccess propertyAccess,
-			ValueGeneration valueGeneration) {
+			ValueGenerationStrategy valueGeneration) {
 		super(
 				attributeName,
 				stateArrayPosition,
@@ -126,7 +126,7 @@ public class BasicAttributeMapping
 			ManagedMappingType declaringType,
 			BasicValuedModelPart original,
 			PropertyAccess propertyAccess,
-			ValueGeneration valueGeneration,
+			ValueGenerationStrategy valueGeneration,
 			boolean insertable,
 			boolean updateable,
 			SelectableMapping selectableMapping) {

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

@@ -54,7 +54,7 @@ import org.hibernate.sql.results.graph.Fetchable;
 import org.hibernate.sql.results.graph.embeddable.EmbeddableValuedFetchable;
 import org.hibernate.sql.results.graph.embeddable.internal.EmbeddableFetchImpl;
 import org.hibernate.sql.results.graph.embeddable.internal.EmbeddableResultImpl;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.ValueGenerationStrategy;
 
 /**
  * @author Steve Ebersole
@@ -80,7 +80,7 @@ public class EmbeddedAttributeMapping
 			EmbeddableMappingType embeddableMappingType,
 			ManagedMappingType declaringType,
 			PropertyAccess propertyAccess,
-			ValueGeneration valueGeneration) {
+			ValueGenerationStrategy valueGeneration) {
 		this(
 			name,
 			navigableRole,
@@ -109,7 +109,7 @@ public class EmbeddedAttributeMapping
 			EmbeddableMappingType embeddableMappingType,
 			ManagedMappingType declaringType,
 			PropertyAccess propertyAccess,
-			ValueGeneration valueGeneration) {
+			ValueGenerationStrategy valueGeneration) {
 		super(
 				name,
 				stateArrayPosition,

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

@@ -88,7 +88,6 @@ import org.hibernate.sql.ast.tree.expression.Expression;
 import org.hibernate.sql.ast.tree.expression.SqlTuple;
 import org.hibernate.sql.ast.tree.from.TableGroup;
 import org.hibernate.sql.ast.tree.from.TableGroupProducer;
-import org.hibernate.tuple.ValueGeneration;
 import org.hibernate.type.AssociationType;
 import org.hibernate.type.BasicType;
 import org.hibernate.type.ComponentType;
@@ -266,7 +265,6 @@ public class MappingModelCreationHelper {
 			fetchTiming = bootProperty.isLazy() ? FetchTiming.DELAYED : FetchTiming.IMMEDIATE;
 			fetchStyle = bootProperty.isLazy() ? FetchStyle.SELECT : FetchStyle.JOIN;
 		}
-		final ValueGeneration valueGeneration = bootProperty.getValueGenerationStrategy();
 
 		return new BasicAttributeMapping(
 				attrName,
@@ -290,7 +288,7 @@ public class MappingModelCreationHelper {
 				attrType,
 				declaringType,
 				propertyAccess,
-				valueGeneration
+				bootProperty.getValueGenerationStrategy()
 		);
 	}
 

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

@@ -17,7 +17,7 @@ import org.hibernate.metamodel.mapping.VirtualModelPart;
 import org.hibernate.metamodel.model.domain.NavigableRole;
 import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.sql.ast.tree.from.TableGroupProducer;
-import org.hibernate.tuple.ValueGeneration;
+import org.hibernate.tuple.ValueGenerationStrategy;
 
 /**
  * @author Christian Beikov
@@ -35,7 +35,8 @@ public class VirtualEmbeddedAttributeMapping extends EmbeddedAttributeMapping im
 			FetchStyle mappedFetchStyle,
 			EmbeddableMappingType embeddableMappingType,
 			ManagedMappingType declaringType,
-			PropertyAccess propertyAccess, ValueGeneration valueGeneration) {
+			PropertyAccess propertyAccess,
+			ValueGenerationStrategy valueGeneration) {
 		super(
 				name,
 				navigableRole,
@@ -63,7 +64,8 @@ public class VirtualEmbeddedAttributeMapping extends EmbeddedAttributeMapping im
 			FetchStyle mappedFetchStyle,
 			EmbeddableMappingType embeddableMappingType,
 			ManagedMappingType declaringType,
-			PropertyAccess propertyAccess, ValueGeneration valueGeneration) {
+			PropertyAccess propertyAccess,
+			ValueGenerationStrategy valueGeneration) {
 		super(
 				name,
 				navigableRole,

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

@@ -256,9 +256,10 @@ import org.hibernate.sql.results.graph.embeddable.EmbeddableResultGraphNode;
 import org.hibernate.sql.results.graph.entity.internal.EntityResultImpl;
 import org.hibernate.sql.results.internal.SqlSelectionImpl;
 import org.hibernate.stat.spi.StatisticsImplementor;
+import org.hibernate.tuple.ValueGenerationStrategy;
+import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 import org.hibernate.tuple.GenerationTiming;
 import org.hibernate.tuple.NonIdentifierAttribute;
-import org.hibernate.tuple.ValueGeneration;
 import org.hibernate.tuple.entity.EntityBasedAssociationAttribute;
 import org.hibernate.tuple.entity.EntityMetamodel;
 import org.hibernate.type.AnyType;
@@ -2758,15 +2759,16 @@ public abstract class AbstractEntityPersister
 						hasColumns = true;
 					}
 					else {
-						final ValueGeneration valueGeneration = attributeMapping.getValueGeneration();
+						final ValueGenerationStrategy valueGeneration = attributeMapping.getValueGeneration();
 						if ( valueGeneration.getGenerationTiming().includesUpdate()
-								&& valueGeneration.generatedByDatabase()
+								&& valueGeneration.generatedByDatabase() ) {
-								&& valueGeneration.referenceColumnInSql() ) {
+							final InDatabaseValueGenerationStrategy generation = (InDatabaseValueGenerationStrategy) valueGeneration;
+							if ( generation.referenceColumnsInSql() ) {
 								final Dialect dialect = getFactory().getJdbcServices().getDialect();
 								update.addColumns(
 										getPropertyColumnNames(index),
 										SINGLE_TRUE,
-									new String[] { valueGeneration.getDatabaseGeneratedReferencedColumnValue(dialect) }
+										generation.getReferencedColumnValues(dialect)
 								);
 								hasColumns = true;
 							}
@@ -2774,6 +2776,7 @@ public abstract class AbstractEntityPersister
 					}
 				}
 			}
+		}
 
 		// HHH-4635
 		// Oracle expects all Lob properties to be last in inserts

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/AbstractMutationCoordinator.java

@@ -9,17 +9,22 @@ package org.hibernate.persister.entity.mutation;
 import java.util.List;
 
 import org.hibernate.Internal;
+import org.hibernate.dialect.Dialect;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.internal.util.collections.CollectionHelper;
+import org.hibernate.metamodel.mapping.AttributeMapping;
 import org.hibernate.persister.entity.AbstractEntityPersister;
 import org.hibernate.sql.model.ModelMutationLogging;
 import org.hibernate.sql.model.MutationOperation;
 import org.hibernate.sql.model.MutationOperationGroup;
 import org.hibernate.sql.model.ValuesAnalysis;
 import org.hibernate.sql.model.ast.MutationGroup;
+import org.hibernate.sql.model.ast.builder.ColumnValuesTableMutationBuilder;
+import org.hibernate.sql.model.ast.builder.MutationGroupBuilder;
 import org.hibernate.sql.model.internal.MutationOperationGroupNone;
 import org.hibernate.sql.model.internal.MutationOperationGroupSingle;
 import org.hibernate.sql.model.internal.MutationOperationGroupStandard;
+import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 
 /**
  * Base support for coordinating mutations against an entity
@@ -84,5 +89,21 @@ public abstract class AbstractMutationCoordinator {
 		);
 	}
 
-
+	void handleValueGeneration(
+			AttributeMapping attributeMapping,
+			MutationGroupBuilder mutationGroupBuilder,
+			InDatabaseValueGenerationStrategy valueGeneration) {
+		final Dialect dialect = factory.getJdbcServices().getDialect();
+		final boolean writePropertyValue = valueGeneration.writePropertyValue();
+		final String[] columnValues = writePropertyValue ? null : valueGeneration.getReferencedColumnValues( dialect );
+		attributeMapping.forEachSelectable( (j, mapping) -> {
+			final String tableName = entityPersister.physicalTableNameForMutation( mapping );
+			final ColumnValuesTableMutationBuilder tableUpdateBuilder = mutationGroupBuilder.findTableDetailsBuilder( tableName );
+			tableUpdateBuilder.addValueColumn(
+					mapping.getSelectionExpression(),
+					writePropertyValue ? "?" : columnValues[j],
+					mapping.getJdbcMapping()
+			);
+		} );
+	}
 }

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/InsertCoordinator.java

@@ -11,7 +11,6 @@ import java.util.List;
 
 import org.hibernate.Internal;
 import org.hibernate.Session;
-import org.hibernate.dialect.Dialect;
 import org.hibernate.engine.jdbc.batch.internal.BasicBatchKey;
 import org.hibernate.engine.jdbc.mutation.JdbcValueBindings;
 import org.hibernate.engine.jdbc.mutation.MutationExecutor;
@@ -24,7 +23,6 @@ import org.hibernate.id.insert.InsertGeneratedIdentifierDelegate;
 import org.hibernate.metamodel.mapping.AttributeMapping;
 import org.hibernate.metamodel.mapping.BasicEntityIdentifierMapping;
 import org.hibernate.metamodel.mapping.PluralAttributeMapping;
-import org.hibernate.metamodel.mapping.internal.BasicAttributeMapping;
 import org.hibernate.persister.entity.AbstractEntityPersister;
 import org.hibernate.sql.model.MutationOperationGroup;
 import org.hibernate.sql.model.MutationType;
@@ -33,8 +31,9 @@ import org.hibernate.sql.model.ValuesAnalysis;
 import org.hibernate.sql.model.ast.builder.MutationGroupBuilder;
 import org.hibernate.sql.model.ast.builder.TableInsertBuilder;
 import org.hibernate.sql.model.ast.builder.TableInsertBuilderStandard;
+import org.hibernate.tuple.ValueGenerationStrategy;
+import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 import org.hibernate.tuple.InMemoryValueGenerationStrategy;
-import org.hibernate.tuple.ValueGeneration;
 import org.hibernate.tuple.entity.EntityMetamodel;
 
 /**
@@ -135,14 +134,7 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 	private Object doStaticInserts(Object id, Object[] values, Object object, SharedSessionContractImplementor session) {
 		final InsertValuesAnalysis insertValuesAnalysis = new InsertValuesAnalysis( entityPersister(), values );
 
-		final TableInclusionChecker tableInclusionChecker = (tableMapping) -> {
+		final TableInclusionChecker tableInclusionChecker = getTableInclusionChecker( insertValuesAnalysis );
-			if ( tableMapping.isOptional() ) {
-				return insertValuesAnalysis.hasNonNullBindings( tableMapping );
-			}
-
-			return true;
-		};
-
 
 		final MutationExecutorService mutationExecutorService = session.getSessionFactory()
 				.getServiceRegistry()
@@ -278,13 +270,7 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 
 		final InsertValuesAnalysis insertValuesAnalysis = new InsertValuesAnalysis( entityPersister(), values );
 
-		final TableInclusionChecker tableInclusionChecker = (tableMapping) -> {
+		final TableInclusionChecker tableInclusionChecker = getTableInclusionChecker( insertValuesAnalysis );
-			if ( tableMapping.isOptional() ) {
-				return insertValuesAnalysis.hasNonNullBindings( tableMapping );
-			}
-
-			return true;
-		};
 
 		decomposeForInsert( mutationExecutor, id, values, insertGroup, insertability, tableInclusionChecker, session );
 
@@ -310,6 +296,10 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 		}
 	}
 
+	private static TableInclusionChecker getTableInclusionChecker(InsertValuesAnalysis insertValuesAnalysis) {
+		return (tableMapping) -> !tableMapping.isOptional() || insertValuesAnalysis.hasNonNullBindings( tableMapping );
+	}
+
 
 	/**
 	 * Transform the array of property indexes to an array of booleans,
@@ -387,8 +377,6 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 			MutationGroupBuilder insertGroupBuilder,
 			boolean[] attributeInclusions) {
 		final List<AttributeMapping> attributeMappings = entityPersister().getAttributeMappings();
-		//noinspection resource
-		final Dialect dialect = factory().getJdbcServices().getDialect();
 
 		insertGroupBuilder.forEachTableMutationBuilder( (builder) -> {
 			final EntityTableMapping tableMapping = (EntityTableMapping) builder.getMutatingTable().getTableMapping();
@@ -402,18 +390,12 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 				final AttributeMapping attributeMapping = attributeMappings.get( attributeIndex );
 
 				if ( !attributeInclusions[ attributeIndex ] ) {
-					final ValueGeneration valueGeneration = attributeMapping.getValueGeneration();
+					final ValueGenerationStrategy valueGeneration = attributeMapping.getValueGeneration();
-					if ( valueGeneration.getGenerationTiming().includesInsert()
+					if ( isValueGenerationInSql( valueGeneration ) ) {
-							&& valueGeneration.getValueGenerator() == null
+						handleValueGeneration(
-							&& valueGeneration.referenceColumnInSql() ) {
+								attributeMapping,
-						// value-generation is only valid for basic attributes
+								insertGroupBuilder,
-						final BasicAttributeMapping basicAttributeMapping = (BasicAttributeMapping) attributeMapping;
+								(InDatabaseValueGenerationStrategy) valueGeneration
-						final String tableNameForMutation = entityPersister().physicalTableNameForMutation( basicAttributeMapping );
-						final TableInsertBuilder tableInsertBuilder = insertGroupBuilder.findTableDetailsBuilder( tableNameForMutation );
-						tableInsertBuilder.addValueColumn(
-								basicAttributeMapping.getSelectionExpression(),
-								valueGeneration.getDatabaseGeneratedReferencedColumnValue( dialect ),
-								basicAttributeMapping.getJdbcMapping()
 						);
 					}
 					continue;
@@ -454,4 +436,10 @@ public class InsertCoordinator extends AbstractMutationCoordinator {
 			}
 		} );
 	}
+
+	private static boolean isValueGenerationInSql(ValueGenerationStrategy valueGeneration) {
+		return valueGeneration.getGenerationTiming().includesInsert()
+				&& valueGeneration.generatedByDatabase()
+				&& ( (InDatabaseValueGenerationStrategy) valueGeneration ).referenceColumnsInSql();
+	}
 }

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/UpdateCoordinatorStandard.java

@@ -14,7 +14,6 @@ import java.util.Set;
 
 import org.hibernate.Internal;
 import org.hibernate.Session;
-import org.hibernate.dialect.Dialect;
 import org.hibernate.engine.OptimisticLockStyle;
 import org.hibernate.engine.jdbc.batch.internal.BasicBatchKey;
 import org.hibernate.engine.jdbc.batch.spi.BatchKey;
@@ -35,7 +34,6 @@ import org.hibernate.metamodel.mapping.AttributeMapping;
 import org.hibernate.metamodel.mapping.EntityRowIdMapping;
 import org.hibernate.metamodel.mapping.EntityVersionMapping;
 import org.hibernate.metamodel.mapping.SingularAttributeMapping;
-import org.hibernate.metamodel.mapping.internal.BasicAttributeMapping;
 import org.hibernate.persister.entity.AbstractEntityPersister;
 import org.hibernate.sql.ast.SqlAstTranslator;
 import org.hibernate.sql.ast.SqlAstTranslatorFactory;
@@ -51,8 +49,9 @@ import org.hibernate.sql.model.ast.builder.TableUpdateBuilderSkipped;
 import org.hibernate.sql.model.ast.builder.TableUpdateBuilderStandard;
 import org.hibernate.sql.model.internal.MutationOperationGroupSingle;
 import org.hibernate.sql.model.jdbc.JdbcMutationOperation;
+import org.hibernate.tuple.ValueGenerationStrategy;
+import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 import org.hibernate.tuple.InMemoryValueGenerationStrategy;
-import org.hibernate.tuple.ValueGeneration;
 import org.hibernate.tuple.entity.EntityMetamodel;
 
 import static org.hibernate.engine.OptimisticLockStyle.ALL;
@@ -213,10 +212,7 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 		}
 
 		final InclusionChecker updateabilityChecker = (position, attribute) -> {
-			final ValueGeneration valueGeneration = attribute.getValueGeneration();
+			if ( isValueGenerationInSql( attribute.getValueGeneration() ) ) {
-			if ( valueGeneration.getGenerationTiming().includesUpdate()
-					&& valueGeneration.getValueGenerator() == null
-					&& valueGeneration.referenceColumnInSql() ) {
 				return true;
 			}
 
@@ -253,8 +249,7 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 
 			if ( optimisticLockStyle == VERSION ) {
 				return versionMapping != null
-						&& versionMapping.getVersionAttribute() == attribute
+						&& versionMapping.getVersionAttribute() == attribute;
-						;
 //						&& updateableAttributeIndexes[position];
 			}
 
@@ -313,6 +308,12 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 		}
 	}
 
+	private static boolean isValueGenerationInSql(ValueGenerationStrategy valueGeneration) {
+		return valueGeneration.getGenerationTiming().includesUpdate()
+				&& valueGeneration.generatedByDatabase()
+				&& ( (InDatabaseValueGenerationStrategy) valueGeneration ).referenceColumnsInSql();
+	}
+
 	/**
 	 * Which properties appear in the SQL update?
 	 * (Initialized, updateable ones!)
@@ -657,16 +658,14 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 				}
 
 				final IncludedAttributeAnalysis attributeAnalysis = (IncludedAttributeAnalysis) attributeAnalysisRef;
-				final ValueGeneration valueGeneration = attributeMapping.getValueGeneration();
 
 				if ( attributeAnalysis.includeInSet() ) {
 					// apply the new values
 					final boolean includeInSet;
 
-					if ( valueGeneration.getGenerationTiming().includesUpdate()
+					final ValueGenerationStrategy valueGeneration = attributeMapping.getValueGeneration();
-							&& valueGeneration.getValueGenerator() == null
+					if ( isValueGenerationInSql( valueGeneration )
-							&& valueGeneration.referenceColumnInSql()
+							&& !( (InDatabaseValueGenerationStrategy) valueGeneration ).writePropertyValue() ) {
-							&& valueGeneration.getDatabaseGeneratedReferencedColumnValue() != null ) {
 						// we applied `#getDatabaseGeneratedReferencedColumnValue` earlier
 						includeInSet = false;
 					}
@@ -881,7 +880,6 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 		final List<AttributeMapping> attributeMappings = entityPersister().getAttributeMappings();
 		final boolean[] versionability = entityPersister().getPropertyVersionability();
 		final OptimisticLockStyle optimisticLockStyle = entityPersister().optimisticLockStyle();
-		final Dialect dialect = factory().getJdbcServices().getDialect();
 
 		updateGroupBuilder.forEachTableMutationBuilder( (builder) -> {
 			final EntityTableMapping tableMapping = (EntityTableMapping) builder.getMutatingTable().getTableMapping();
@@ -898,21 +896,12 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 				if ( attributeAnalysis.includeInSet() ) {
 					assert updateValuesAnalysis.tablesNeedingUpdate.contains( tableMapping );
 
-					final ValueGeneration valueGeneration = attributeMapping.getValueGeneration();
+					final ValueGenerationStrategy valueGeneration = attributeMapping.getValueGeneration();
-					if ( valueGeneration.getGenerationTiming().includesUpdate()
+					if ( isValueGenerationInSql( valueGeneration ) ) {
-							&& valueGeneration.getValueGenerator() == null
+						handleValueGeneration(
-							&& valueGeneration.referenceColumnInSql() ) {
+								attributeMapping,
-						// value-generation is only valid for basic attributes
+								updateGroupBuilder,
-						final BasicAttributeMapping basicAttributeMapping = (BasicAttributeMapping) attributeMapping;
+								(InDatabaseValueGenerationStrategy) valueGeneration
-						final String databaseGeneratedValue = valueGeneration.getDatabaseGeneratedReferencedColumnValue(
-								dialect
-						);
-						tableUpdateBuilder.addValueColumn(
-								basicAttributeMapping.getSelectionExpression(),
-								databaseGeneratedValue == null
-										? "?"
-										: databaseGeneratedValue,
-								basicAttributeMapping.getJdbcMapping()
 						);
 					}
 					else if ( versionMapping != null
@@ -1014,7 +1003,6 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 		} );
 	}
 
-
 	/**
 	 * Contains the aggregated analysis of the update values to determine
 	 * what SQL UPDATE statement(s) should be used to update the entity
@@ -1344,10 +1332,7 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 				null,
 				null,
 				(index,attribute) -> {
-					final ValueGeneration valueGeneration = attribute.getValueGeneration();
+					if ( isValueGenerationInSql( attribute.getValueGeneration() ) ) {
-					if ( valueGeneration.getGenerationTiming().includesUpdate()
-							&& valueGeneration.getValueGenerator() == null
-							&& valueGeneration.referenceColumnInSql() ) {
 						return true;
 					}
 

hibernate-core/src/main/java/org/hibernate/sql/ast/spi/SqlExpressionResolver.java

@@ -6,7 +6,6 @@
  */
 package org.hibernate.sql.ast.spi;
 
-import java.util.Objects;
 import java.util.function.Function;
 
 import org.hibernate.metamodel.mapping.SelectableMapping;

hibernate-core/src/main/java/org/hibernate/sql/model/ast/builder/ColumnValuesTableMutationBuilder.java

@@ -0,0 +1,50 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html.
+ */
+package org.hibernate.sql.model.ast.builder;
+
+import org.hibernate.metamodel.mapping.JdbcMapping;
+import org.hibernate.metamodel.mapping.SelectableMapping;
+
+/**
+ * Common operations of {@link TableUpdateBuilder} and {@link TableInsertBuilder}.
+ *
+ * @author Steve Ebersole
+ * @author Gavin King
+ */
+public interface ColumnValuesTableMutationBuilder {
+	/**
+	 * Add a column as part of the values list
+	 */
+	void addValueColumn(String columnName, String columnWriteFragment, JdbcMapping jdbcMapping);
+
+	/**
+	 * Add a column as part of the values list
+	 */
+	default void addValueColumn(SelectableMapping selectableMapping) {
+		addValueColumn(
+				selectableMapping.getSelectionExpression(),
+				selectableMapping.getWriteExpression(),
+				selectableMapping.getJdbcMapping()
+		);
+	}
+
+	/**
+	 * Add a key column
+	 */
+	void addKeyColumn(String columnName, String valueExpression, JdbcMapping jdbcMapping);
+
+	/**
+	 * Add a key column
+	 */
+	default void addKeyColumn(SelectableMapping selectableMapping) {
+		addKeyColumn(
+				selectableMapping.getSelectionExpression(),
+				selectableMapping.getWriteExpression(),
+				selectableMapping.getJdbcMapping()
+		);
+	}
+}

hibernate-core/src/main/java/org/hibernate/sql/model/ast/builder/RestrictedTableMutationBuilder.java

@@ -13,8 +13,10 @@ import org.hibernate.sql.model.MutationOperation;
 import org.hibernate.sql.model.ast.RestrictedTableMutation;
 
 /**
- * Specialized TableMutationBuilder implementation for building mutations
+ * Specialized {@link TableMutationBuilder} implementation for building mutations
- * which define a where-clause
+ * which have a {@code where} clause.
+ *
+ * Common operations of {@link TableUpdateBuilder} and {@link TableDeleteBuilder}.
  *
  * @author Steve Ebersole
  */

hibernate-core/src/main/java/org/hibernate/sql/model/ast/builder/TableDeleteBuilder.java

@@ -10,6 +10,8 @@ import org.hibernate.sql.model.ast.TableDelete;
 import org.hibernate.sql.model.jdbc.JdbcDeleteMutation;
 
 /**
+ * {@link TableMutationBuilder} implementation for {@code delete} statements.
+ *
  * @author Steve Ebersole
  */
 public interface TableDeleteBuilder extends RestrictedTableMutationBuilder<JdbcDeleteMutation, TableDelete> {

hibernate-core/src/main/java/org/hibernate/sql/model/ast/builder/TableInsertBuilder.java

@@ -6,45 +6,13 @@
  */
 package org.hibernate.sql.model.ast.builder;
 
-import org.hibernate.metamodel.mapping.JdbcMapping;
-import org.hibernate.metamodel.mapping.SelectableMapping;
 import org.hibernate.sql.model.ast.TableInsert;
 
 /**
- * TableMutationBuilder implementation for insert statements
+ * {@link TableMutationBuilder} implementation for {@code insert} statements.
  *
  * @author Steve Ebersole
  */
-public interface TableInsertBuilder extends TableMutationBuilder<TableInsert> {
+public interface TableInsertBuilder extends TableMutationBuilder<TableInsert>, ColumnValuesTableMutationBuilder {
-	/**
-	 * Add a column as part of the values list
-	 */
-	default void addValueColumn(SelectableMapping selectableMapping) {
-		addValueColumn(
-				selectableMapping.getSelectionExpression(),
-				selectableMapping.getWriteExpression(),
-				selectableMapping.getJdbcMapping()
-		);
-	}
 
-	/**
-	 * Add a column as part of the values list
-	 */
-	void addValueColumn(String columnName, String columnWriteFragment, JdbcMapping jdbcMapping);
-
-	/**
-	 * Add a key column
-	 */
-	default void addKeyColumn(SelectableMapping selectableMapping) {
-		addKeyColumn(
-				selectableMapping.getSelectionExpression(),
-				selectableMapping.getWriteExpression(),
-				selectableMapping.getJdbcMapping()
-		);
-	}
-
-	/**
-	 * Add a key column
-	 */
-	void addKeyColumn(String columnName, String valueExpression, JdbcMapping jdbcMapping);
 }

hibernate-core/src/main/java/org/hibernate/sql/model/ast/builder/TableUpdateBuilder.java

@@ -6,28 +6,18 @@
  */
 package org.hibernate.sql.model.ast.builder;
 
-import org.hibernate.metamodel.mapping.JdbcMapping;
 import org.hibernate.metamodel.mapping.SelectableConsumer;
 import org.hibernate.metamodel.mapping.SelectableMapping;
 import org.hibernate.sql.model.MutationOperation;
 import org.hibernate.sql.model.ast.RestrictedTableMutation;
 
 /**
+ * {@link TableMutationBuilder} implementation for {@code update} statements.
+ *
  * @author Steve Ebersole
  */
 public interface TableUpdateBuilder<O extends MutationOperation>
-		extends RestrictedTableMutationBuilder<O, RestrictedTableMutation<O>> {
+		extends RestrictedTableMutationBuilder<O, RestrictedTableMutation<O>>, ColumnValuesTableMutationBuilder {
-
-	/**
-	 * Add a column as part of the values list
-	 */
-	default void addValueColumn(SelectableMapping selectableMapping) {
-		addValueColumn(
-				selectableMapping.getSelectionExpression(),
-				selectableMapping.getWriteExpression(),
-				selectableMapping.getJdbcMapping()
-		);
-	}
 
 	/**
 	 * Convenience form of {@link #addValueColumn(SelectableMapping)} matching the
@@ -42,26 +32,5 @@ public interface TableUpdateBuilder<O extends MutationOperation>
 		addValueColumn( selectableMapping );
 	}
 
-	/**
-	 * Add a column as part of the values list
-	 */
-	void addValueColumn(String columnName, String columnWriteFragment, JdbcMapping jdbcMapping);
-
-	/**
-	 * Add a key column
-	 */
-	default void addKeyColumn(SelectableMapping selectableMapping) {
-		addKeyColumn(
-				selectableMapping.getSelectionExpression(),
-				selectableMapping.getWriteExpression(),
-				selectableMapping.getJdbcMapping()
-		);
-	}
-
-	/**
-	 * Add a key column
-	 */
-	void addKeyColumn(String columnName, String valueExpression, JdbcMapping jdbcMapping);
-
 	void setWhere(String fragment);
 }

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

@@ -69,7 +69,7 @@ public abstract class AbstractNonIdentifierAttribute extends AbstractAttribute i
 	}
 
 	@Override
-	public ValueGeneration getValueGenerationStrategy() {
+	public ValueGenerationStrategy getValueGenerationStrategy() {
 		return attributeInformation.getValueGenerationStrategy();
 	}
 

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

@@ -16,7 +16,7 @@ public class BaselineAttributeInformation {
 	private final boolean lazy;
 	private final boolean insertable;
 	private final boolean updateable;
-	private final ValueGeneration valueGenerationStrategy;
+	private final ValueGenerationStrategy valueGenerationStrategy;
 	private final boolean nullable;
 	private final boolean dirtyCheckable;
 	private final boolean versionable;
@@ -28,7 +28,7 @@ public class BaselineAttributeInformation {
 			boolean lazy,
 			boolean insertable,
 			boolean updateable,
-			ValueGeneration valueGenerationStrategy,
+			ValueGenerationStrategy valueGenerationStrategy,
 			boolean nullable,
 			boolean dirtyCheckable,
 			boolean versionable,
@@ -57,7 +57,7 @@ public class BaselineAttributeInformation {
 		return updateable;
 	}
 
-	public ValueGeneration getValueGenerationStrategy() {
+	public ValueGenerationStrategy getValueGenerationStrategy() {
 		return valueGenerationStrategy;
 	}
 
@@ -89,7 +89,7 @@ public class BaselineAttributeInformation {
 		private boolean lazy;
 		private boolean insertable;
 		private boolean updateable;
-		private ValueGeneration valueGenerationStrategy;
+		private ValueGenerationStrategy valueGenerationStrategy;
 		private boolean nullable;
 		private boolean dirtyCheckable;
 		private boolean versionable;
@@ -111,7 +111,7 @@ public class BaselineAttributeInformation {
 			return this;
 		}
 
-		public Builder setValueGenerationStrategy(ValueGeneration valueGenerationStrategy) {
+		public Builder setValueGenerationStrategy(ValueGenerationStrategy valueGenerationStrategy) {
 			this.valueGenerationStrategy = valueGenerationStrategy;
 			return this;
 		}

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

@@ -6,37 +6,63 @@
  */
 package org.hibernate.tuple;
 
+import org.hibernate.dialect.Dialect;
+
 /**
- * Strategy for describing values which are generated in the database.
+ * A value generated by the database might be generated implicitly, by a trigger, or using
+ * a {@code default} column value specified in DDL, for example, or it might be generated
+ * by a SQL expression occurring explicitly in the SQL {@code insert} or {@code update}
+ * statement. In this case, the generated value is retrieved from the database using a SQL
+ * {@code select}.
  *
  * @author Steve Ebersole
  */
-public interface InDatabaseValueGenerationStrategy {
+public interface InDatabaseValueGenerationStrategy extends ValueGenerationStrategy {
-	/**
-	 * When is this value generated : NEVER, INSERT, ALWAYS (INSERT+UPDATE)
-	 *
-	 * @return When the value is generated.
-	 */
-	GenerationTiming getGenerationTiming();
 
 	/**
-	 * Should the column(s) be referenced in the INSERT / UPDATE SQL?
+	 * Determines if the columns whose values are generated are included in the column list of
-	 * <p>
+	 * the SQL {@code insert} or {@code update} statement, in the case where the value is
-	 * This will be {@code false} most often to have a DDL-defined DEFAULT value be applied on INSERT.  For
+	 * generated by the database. For example, this method should return:
-	 * trigger-generated values this could be {@code true} or {@code false} depending on whether the user wants
+	 * <ul>
-	 * the trigger to have access to some value for the column passed in.
+	 * <li>{@code true} if the value is generated by calling a SQL function like
+	 *     {@code current_timestamp}, or
+	 * <li>{@code false} if the value is generated by a trigger,
+	 *     by {@link org.hibernate.annotations.GeneratedColumn generated always as}, or
+	 *     using a {@linkplain org.hibernate.annotations.ColumnDefault column default value}.
+	 * </ul>
+	 * If the value is generated in Java, this method is not called, and so for backward
+	 * compatibility with Hibernate 5 it is permitted to return any value. On the other hand,
+	 * when a property value is generated in Java, the column certainly must be included in
+	 * the column list, and so it's most correct for this method to return {@code true}!
 	 *
-	 * @return {@code true} indicates the column should be included in the SQL.
+	 * @return {@code true} if the column is included in the column list of the SQL statement.
 	 */
 	boolean referenceColumnsInSql();
 
 	/**
-	 * For columns that will be referenced in the SQL (per {@link #referenceColumnsInSql()}), what value
+	 * Determines if the property values are written to JDBC as the argument of a JDBC {@code ?}
-	 * should be used in the SQL as the column value.
+	 * parameter.
-	 *
-	 * @return The column value to be used in the SQL.  {@code null} for any element indicates to use the Column
-	 * defined value ({@link org.hibernate.mapping.Column#getWriteExpr}).
 	 */
-	String[] getReferencedColumnValues();
+	boolean writePropertyValue();
 
+	/**
+	 * A SQL expression indicating how to calculate the generated values when the property values
+	 * are {@linkplain #generatedByDatabase() generated in the database} and the mapped columns
+	 * are {@linkplain #referenceColumnsInSql() included in the SQL statement}. The SQL expressions
+	 * might be:
+	 * <ul>
+	 * <li>function calls like {@code current_timestamp} or {@code nextval('mysequence')}, or
+	 * <li>syntactic markers like {@code default}.
+	 * </ul>
+	 * When the property values are generated in Java, this method is not called.
+	 *
+	 * @param dialect The {@linkplain Dialect SQL dialect}, allowing generation of an expression
+	 *				in dialect-specific SQL.
+	 * @return The column value to be used in the generated SQL statement.
+	 */
+	String[] getReferencedColumnValues(Dialect dialect);
+
+	default boolean generatedByDatabase() {
+		return true;
+	}
 }

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

@@ -7,23 +7,23 @@
 package org.hibernate.tuple;
 
 /**
+ * Java value generation is the responsibility of an associated {@link ValueGenerator}.
+ * In this case, the generated value is written to the database just like any other field
+ * or property value.
+ *
  * @author Steve Ebersole
  */
-public interface InMemoryValueGenerationStrategy {
+public interface InMemoryValueGenerationStrategy extends ValueGenerationStrategy {
-	/**
-	 * When is this value generated : NEVER, INSERT, ALWAYS (INSERT+UPDATE)
-	 *
-	 * @return When the value is generated.
-	 */
-	GenerationTiming getGenerationTiming();
 
 	/**
-	 * Obtain the in-VM value generator.
+	 * Obtain the {@linkplain ValueGenerator Java value generator}, if the value is generated in
-	 * <p>
+	 * Java, or return {@code null} if the value is generated by the database.
-	 * May return {@code null}.  In fact for values that are generated "in the database" via execution of the
-	 * INSERT/UPDATE statement, the expectation is that {@code null} be returned here
 	 *
-	 * @return The strategy for performing in-VM value generation
+	 * @return The value generator
 	 */
 	ValueGenerator<?> getValueGenerator();
+
+	default boolean generatedByDatabase() {
+		return false;
+	}
 }

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

@@ -19,7 +19,7 @@ public interface NonIdentifierAttribute extends Attribute {
 
 	boolean isUpdateable();
 
-	ValueGeneration getValueGenerationStrategy();
+	ValueGenerationStrategy getValueGenerationStrategy();
 
 	boolean isNullable();
 

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

@@ -6,24 +6,16 @@
  */
 package org.hibernate.tuple;
 
-import java.lang.reflect.Constructor;
-
 import org.hibernate.HibernateException;
 import org.hibernate.boot.spi.MetadataImplementor;
 import org.hibernate.boot.spi.SessionFactoryOptions;
 import org.hibernate.bytecode.enhance.spi.interceptor.EnhancementHelper;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.id.IdentifierGenerator;
-import org.hibernate.internal.util.ReflectHelper;
 import org.hibernate.mapping.PersistentClass;
 import org.hibernate.mapping.Property;
-import org.hibernate.metamodel.RepresentationMode;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.persister.entity.EntityPersister;
-import org.hibernate.property.access.spi.Getter;
-import org.hibernate.property.access.spi.PropertyAccess;
-import org.hibernate.property.access.spi.PropertyAccessStrategy;
-import org.hibernate.property.access.spi.PropertyAccessStrategyResolver;
 import org.hibernate.tuple.entity.EntityBasedAssociationAttribute;
 import org.hibernate.tuple.entity.EntityBasedBasicAttribute;
 import org.hibernate.tuple.entity.EntityBasedCompositionAttribute;

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

@@ -42,7 +42,7 @@ public class StandardProperty extends AbstractNonIdentifierAttribute implements
 			boolean lazy,
 			boolean insertable,
 			boolean updateable,
-			ValueGeneration valueGenerationStrategy,
+			ValueGenerationStrategy valueGenerationStrategy,
 			boolean nullable,
 			boolean checkable,
 			boolean versionable,

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

@@ -8,50 +8,14 @@ package org.hibernate.tuple;
 
 import org.hibernate.dialect.Dialect;
 
-import java.io.Serializable;
-
 /**
- * Describes the generation of values of a certain field or property of an entity. A generated
+ * A value generator that can adapt to both Java value generation and database value
- * value might be generated in Java, or by the database.
+ * generation.
- * <ul>
- * <li>Java value generation is the responsibility of an associated {@link ValueGenerator}.
- *     In this case, the generated value is written to the database just like any other field
- *     or property value.
- * <li>A value generated by the database might be generated implicitly, by a trigger, or using
- *     a {@code default} column value specified in DDL, for example, or it might be generated
- *     by a SQL expression occurring explicitly in the SQL {@code insert} or {@code update}
- *     statement. In this case, the generated value is retrieved from the database using a SQL
- *     {@code select}.
- * </ul>
- *
- * @see org.hibernate.annotations.ValueGenerationType
- * @see org.hibernate.annotations.Generated
- * @see org.hibernate.annotations.GeneratorType
  *
  * @author Steve Ebersole
+ * @author Gavin King
  */
-public interface ValueGeneration extends Serializable {
+public interface ValueGeneration extends InMemoryValueGenerationStrategy, InDatabaseValueGenerationStrategy {
-	/**
-	 * Specifies that the property value is generated:
-	 * <ul>
-	 * <li>{@linkplain GenerationTiming#INSERT when the entity is inserted},
-	 * <li>{@linkplain GenerationTiming#UPDATE when the entity is updated},
-	 * <li>{@linkplain GenerationTiming#ALWAYS whenever the entity is inserted or updated}, or
-	 * <li>{@linkplain GenerationTiming#NEVER never}.
-	 * </ul>
-	 *
-	 * @return The {@link GenerationTiming} specifying when the value is generated.
-	 */
-	GenerationTiming getGenerationTiming();
-
-	/**
-	 * Obtain the {@linkplain ValueGenerator Java value generator}, if the value is generated in
-	 * Java, or return {@code null} if the value is generated by the database.
-	 *
-	 * @return The value generator
-	 */
-	ValueGenerator<?> getValueGenerator();
-
 	/**
 	 * Determines if the column whose value is generated is included in the column list of the
 	 * SQL {@code insert} or {@code update} statement, in the case where the value is generated
@@ -110,6 +74,17 @@ public interface ValueGeneration extends Serializable {
 		return getDatabaseGeneratedReferencedColumnValue();
 	}
 
+	@Override
+	default String[] getReferencedColumnValues(Dialect dialect) {
+		String columnValue = getDatabaseGeneratedReferencedColumnValue( dialect );
+		return columnValue == null ? null : new String[] { columnValue };
+	}
+
+	@Override
+	default boolean referenceColumnsInSql() {
+		return referenceColumnInSql();
+	}
+
 	/**
 	 * Determines if the property value is generated in Java, or by the database.
 	 * <p>
@@ -137,6 +112,6 @@ public interface ValueGeneration extends Serializable {
 	default boolean writePropertyValue() {
 		return !generatedByDatabase() // value generated in memory and then written as normal
 			// current value of property of entity instance written completely as normal
-			|| referenceColumnInSql() && getDatabaseGeneratedReferencedColumnValue()==null;
+			|| referenceColumnsInSql() && getDatabaseGeneratedReferencedColumnValue()==null;
 	}
 }

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

@@ -0,0 +1,52 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.tuple;
+
+import java.io.Serializable;
+
+/**
+ * Describes the generation of values of a certain field or property of an entity. A generated
+ * value might be generated in Java, or by the database.
+ * <ul>
+ * <li>Java value generation is the responsibility of an associated {@link ValueGenerator}.
+ *	 In this case, the generated value is written to the database just like any other field
+ *	 or property value.
+ * <li>A value generated by the database might be generated implicitly, by a trigger, or using
+ *	 a {@code default} column value specified in DDL, for example, or it might be generated
+ *	 by a SQL expression occurring explicitly in the SQL {@code insert} or {@code update}
+ *	 statement. In this case, the generated value is retrieved from the database using a SQL
+ *	 {@code select}.
+ * </ul>
+ *
+ * @see org.hibernate.annotations.ValueGenerationType
+ * @see org.hibernate.annotations.Generated
+ * @see org.hibernate.annotations.GeneratorType
+ *
+ * @author Steve Ebersole
+ * @author Gavin King
+ */
+public interface ValueGenerationStrategy extends Serializable {
+	/**
+	 * Specifies that the property value is generated:
+	 * <ul>
+	 * <li>{@linkplain GenerationTiming#INSERT when the entity is inserted},
+	 * <li>{@linkplain GenerationTiming#UPDATE when the entity is updated},
+	 * <li>{@linkplain GenerationTiming#ALWAYS whenever the entity is inserted or updated}, or
+	 * <li>{@linkplain GenerationTiming#NEVER never}.
+	 * </ul>
+	 *
+	 * @return The {@link GenerationTiming} specifying when the value is generated.
+	 */
+	GenerationTiming getGenerationTiming();
+
+	/**
+	 * Determines if the property value is generated in Java, or by the database.
+	 * @return {@code true} if the value is generated by the database, or false if it is
+	 *		 generated in Java using a {@link ValueGenerator}.
+	 */
+	boolean generatedByDatabase();
+}

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

@@ -40,13 +40,13 @@ import org.hibernate.mapping.Subclass;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.persister.spi.PersisterCreationContext;
+import org.hibernate.tuple.ValueGenerationStrategy;
+import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 import org.hibernate.tuple.GenerationTiming;
 import org.hibernate.tuple.IdentifierProperty;
-import org.hibernate.tuple.InDatabaseValueGenerationStrategy;
 import org.hibernate.tuple.InMemoryValueGenerationStrategy;
 import org.hibernate.tuple.NonIdentifierAttribute;
 import org.hibernate.tuple.PropertyFactory;
-import org.hibernate.tuple.ValueGeneration;
 import org.hibernate.tuple.ValueGenerator;
 import org.hibernate.type.AssociationType;
 import org.hibernate.type.CollectionType;
@@ -458,28 +458,25 @@ public class EntityMetamodel implements Serializable {
 	private static GenerationStrategyPair buildGenerationStrategyPair(
 			final SessionFactoryImplementor sessionFactory,
 			final Property mappingProperty) {
-		final ValueGeneration valueGeneration = mappingProperty.getValueGenerationStrategy();
+		final ValueGenerationStrategy valueGeneration = mappingProperty.getValueGenerationStrategy();
 		if ( valueGeneration != null && valueGeneration.getGenerationTiming() != GenerationTiming.NEVER ) {
 			// the property is generated in full. build the generation strategy pair.
 			if ( !valueGeneration.generatedByDatabase() ) {
 				// in-memory generation
 				return new GenerationStrategyPair(
-						FullInMemoryValueGenerationStrategy.create( valueGeneration )
+						FullInMemoryValueGenerationStrategy.create( (InMemoryValueGenerationStrategy) valueGeneration )
 				);
 			}
 			else {
 				// in-db generation
-				return new GenerationStrategyPair(
+				return new GenerationStrategyPair( (InDatabaseValueGenerationStrategy) valueGeneration );
-						create(
-								sessionFactory,
-								mappingProperty,
-								valueGeneration
-						)
-				);
 			}
 		}
 		else if ( mappingProperty.getValue() instanceof Component ) {
-			final CompositeGenerationStrategyPairBuilder builder = new CompositeGenerationStrategyPairBuilder( mappingProperty );
+			final CompositeGenerationStrategyPairBuilder builder = new CompositeGenerationStrategyPairBuilder(
+					mappingProperty,
+					sessionFactory.getJdbcServices().getDialect()
+			);
 			interpretPartialCompositeValueGeneration( sessionFactory, (Component) mappingProperty.getValue(), builder );
 			return builder.buildPair();
 		}
@@ -498,36 +495,6 @@ public class EntityMetamodel implements Serializable {
 		}
 	}
 
-	public static InDatabaseValueGenerationStrategyImpl create(
-			SessionFactoryImplementor factory,
-			Property mappingProperty,
-			ValueGeneration valueGeneration) {
-		final int numberOfMappedColumns = mappingProperty.getType().getColumnSpan( factory );
-		final Dialect dialect = factory.getJdbcServices().getDialect();
-		if ( numberOfMappedColumns == 1 ) {
-			return new InDatabaseValueGenerationStrategyImpl(
-					valueGeneration.getGenerationTiming(),
-					valueGeneration.referenceColumnInSql(),
-					new String[] { valueGeneration.getDatabaseGeneratedReferencedColumnValue(dialect) }
-
-			);
-		}
-		else {
-			if ( valueGeneration.getDatabaseGeneratedReferencedColumnValue(dialect) != null ) {
-				LOG.debugf(
-						"Value generator specified column value in reference to multi-column attribute [%s -> %s]; ignoring",
-						mappingProperty.getPersistentClass(),
-						mappingProperty.getName()
-				);
-			}
-			return new InDatabaseValueGenerationStrategyImpl(
-					valueGeneration.getGenerationTiming(),
-					valueGeneration.referenceColumnInSql(),
-					new String[numberOfMappedColumns]
-			);
-		}
-	}
-
 	public static class GenerationStrategyPair {
 		private final InMemoryValueGenerationStrategy inMemoryStrategy;
 		private final InDatabaseValueGenerationStrategy inDatabaseStrategy;
@@ -540,7 +507,7 @@ public class EntityMetamodel implements Serializable {
 			this( inMemoryStrategy, NoInDatabaseValueGenerationStrategy.INSTANCE );
 		}
 
-		public GenerationStrategyPair(InDatabaseValueGenerationStrategyImpl inDatabaseStrategy) {
+		public GenerationStrategyPair(InDatabaseValueGenerationStrategy inDatabaseStrategy) {
 			this( NoInMemoryValueGenerationStrategy.INSTANCE, inDatabaseStrategy );
 		}
 
@@ -583,14 +550,16 @@ public class EntityMetamodel implements Serializable {
 
 	private static class CompositeGenerationStrategyPairBuilder {
 		private final Property mappingProperty;
+		private final Dialect dialect;
 
 		private boolean hadInMemoryGeneration;
 		private boolean hadInDatabaseGeneration;
 
 		private List<InDatabaseValueGenerationStrategy> inDatabaseStrategies;
 
-		public CompositeGenerationStrategyPairBuilder(Property mappingProperty) {
+		public CompositeGenerationStrategyPairBuilder(Property mappingProperty, Dialect dialect) {
 			this.mappingProperty = mappingProperty;
+			this.dialect = dialect;
 		}
 
 		public void addPair(GenerationStrategyPair generationStrategyPair) {
@@ -675,8 +644,8 @@ public class EntityMetamodel implements Serializable {
 						// override base-line value
 						referenceColumns = true;
 					}
-					if ( subStrategy.getReferencedColumnValues() != null ) {
+					if ( subStrategy.getReferencedColumnValues(dialect) != null ) {
-						if ( subStrategy.getReferencedColumnValues().length != property.getColumnSpan() ) {
+						if ( subStrategy.getReferencedColumnValues(dialect).length != property.getColumnSpan() ) {
 							throw new ValueGenerationStrategyException(
 									"Internal error : mismatch between number of collected 'referenced column values'" +
 											" and number of columns for composite attribute : " + mappingProperty.getName() +
@@ -684,7 +653,7 @@ public class EntityMetamodel implements Serializable {
 							);
 						}
 						System.arraycopy(
-								subStrategy.getReferencedColumnValues(),
+								subStrategy.getReferencedColumnValues(dialect),
 								0,
 								columnValues,
 								columnIndex,
@@ -730,7 +699,7 @@ public class EntityMetamodel implements Serializable {
 			this.generator = generator;
 		}
 
-		public static FullInMemoryValueGenerationStrategy create(ValueGeneration valueGeneration) {
+		public static FullInMemoryValueGenerationStrategy create(InMemoryValueGenerationStrategy valueGeneration) {
 			return new FullInMemoryValueGenerationStrategy(
 					valueGeneration.getGenerationTiming(),
 					valueGeneration.getValueGenerator()
@@ -765,9 +734,14 @@ public class EntityMetamodel implements Serializable {
 		}
 
 		@Override
-		public String[] getReferencedColumnValues() {
+		public String[] getReferencedColumnValues(Dialect dialect) {
 			return null;
 		}
+
+		@Override
+		public boolean writePropertyValue() {
+			return true;
+		}
 	}
 
 	private static class InDatabaseValueGenerationStrategyImpl implements InDatabaseValueGenerationStrategy {
@@ -795,9 +769,14 @@ public class EntityMetamodel implements Serializable {
 		}
 
 		@Override
-		public String[] getReferencedColumnValues() {
+		public String[] getReferencedColumnValues(Dialect dialect) {
 			return referencedColumnValues;
 		}
+
+		@Override
+		public boolean writePropertyValue() {
+			return false;
+		}
 	}
 
 

hibernate-core/src/main/java/org/hibernate/type/ComponentType.java

@@ -35,6 +35,7 @@ import org.hibernate.metamodel.spi.EmbeddableInstantiator;
 import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.query.sqm.SqmExpressible;
 import org.hibernate.resource.beans.spi.ManagedBeanRegistry;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.tuple.PropertyFactory;
 import org.hibernate.tuple.StandardProperty;
 import org.hibernate.tuple.ValueGeneration;
@@ -52,7 +53,7 @@ public class ComponentType extends AbstractType implements CompositeTypeImplemen
 
 	private final String[] propertyNames;
 	private final Type[] propertyTypes;
-	private final ValueGeneration[] propertyValueGenerationStrategies;
+	private final ValueGenerationStrategy[] propertyValueGenerationStrategies;
 	private final boolean[] propertyNullability;
 	private final int[] originalPropertyOrder;
 	protected final int propertySpan;
@@ -437,7 +438,7 @@ public class ComponentType extends AbstractType implements CompositeTypeImplemen
 		return propertyTypes;
 	}
 
-	public ValueGeneration[] getPropertyValueGenerationStrategies() {
+	public ValueGenerationStrategy[] getPropertyValueGenerationStrategies() {
 		return propertyValueGenerationStrategies;
 	}
 

hibernate-envers/src/main/java/org/hibernate/envers/configuration/internal/metadata/AuditMetadataGenerator.java

@@ -33,9 +33,8 @@ import org.hibernate.envers.internal.entities.mapper.SubclassPropertyMapper;
 import org.hibernate.mapping.PersistentClass;
 import org.hibernate.mapping.Property;
 import org.hibernate.mapping.SyntheticProperty;
+import org.hibernate.tuple.ValueGenerationStrategy;
 import org.hibernate.tuple.GeneratedValueGeneration;
-import org.hibernate.tuple.GenerationTiming;
-import org.hibernate.tuple.ValueGeneration;
 
 import org.jboss.logging.Logger;
 
@@ -120,7 +119,7 @@ public final class AuditMetadataGenerator extends AbstractMetadataGenerator {
 
 	private boolean isPropertyInsertable(Property property) {
 		if ( !property.isInsertable() ) {
-			final ValueGeneration generation = property.getValueGenerationStrategy();
+			final ValueGenerationStrategy generation = property.getValueGenerationStrategy();
 			if ( generation instanceof GeneratedValueGeneration ) {
 				final GeneratedValueGeneration valueGeneration = (GeneratedValueGeneration) generation;
 				if ( valueGeneration.getGenerationTiming().includesInsert() ) {