HHH-17653 - Error in generating schema when @Generator annotation is applied to a non id embeddable property

hibernate-core/src/main/java/org/hibernate/boot/model/internal/EmbeddableBinder.java

@@ -388,8 +388,16 @@ public class EmbeddableBinder {
 
 			final XProperty property = propertyAnnotatedElement.getProperty();
 			if ( property.isAnnotationPresent( GeneratedValue.class ) ) {
+				if ( isIdClass || subholder.isOrWithinEmbeddedId() ) {
 					processGeneratedId( context, component, property );
 				}
+				else {
+					throw new AnnotationException(
+							"Property '" + property.getName() + "' of '"
+									+ getPath( propertyHolder, inferredData )
+									+ "' is annotated '@GeneratedValue' but is not part of an identifier" );
+				}
+			}
 		}
 
 		if ( compositeUserType != null ) {

hibernate-core/src/main/java/org/hibernate/boot/model/internal/EntityBinder.java

@@ -67,6 +67,7 @@ import org.hibernate.annotations.Where;
 import org.hibernate.annotations.common.reflection.ReflectionManager;
 import org.hibernate.annotations.common.reflection.XAnnotatedElement;
 import org.hibernate.annotations.common.reflection.XClass;
+import org.hibernate.annotations.common.reflection.XProperty;
 import org.hibernate.binder.TypeBinder;
 import org.hibernate.boot.model.IdentifierGeneratorDefinition;
 import org.hibernate.boot.model.NamedEntityGraphDefinition;
@@ -116,6 +117,7 @@ import jakarta.persistence.ConstraintMode;
 import jakarta.persistence.DiscriminatorColumn;
 import jakarta.persistence.DiscriminatorValue;
 import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.IdClass;
 import jakarta.persistence.Inheritance;
 import jakarta.persistence.InheritanceType;
@@ -1015,14 +1017,22 @@ public class EntityBinder {
 		for ( PropertyData propertyAnnotatedElement : elementsToProcess.getElements() ) {
 			final String propertyName = propertyAnnotatedElement.getPropertyName();
 			if ( !idPropertiesIfIdClass.contains( propertyName ) ) {
+				final XProperty property = propertyAnnotatedElement.getProperty();
+				boolean hasIdAnnotation = hasIdAnnotation( property );
 				if ( !idPropertiesIfIdClass.isEmpty() && !isIgnoreIdAnnotations()
-						&& hasIdAnnotation( propertyAnnotatedElement.getProperty() ) ) {
+						&& hasIdAnnotation ) {
 					missingEntityProperties.add( propertyName );
 				}
 				else {
 					boolean subclassAndSingleTableStrategy =
 							inheritanceState.getType() == InheritanceType.SINGLE_TABLE
 									&& inheritanceState.hasParents();
+					if ( !hasIdAnnotation && property.isAnnotationPresent( GeneratedValue.class ) ) {
+						throw new AnnotationException(
+								"Property '"
+										+ BinderHelper.getPath( propertyHolder, propertyAnnotatedElement )
+										+ "' is annotated @GeneratedValue but is not part of an identifier" );
+					}
 					processElementAnnotations(
 							propertyHolder,
 							subclassAndSingleTableStrategy

migration-guide.adoc

@@ -76,3 +76,27 @@ Finally, the `SelfRenderingFunctionSqlAstExpression.getRenderer()` method was de
 == Supported Dialects
 
 Please also do have a look at the link:{versionDocBase}/dialect/dialect.html[Supported Dialects] document to check for potential upgrades to the minimum version of the databases underpinning the dialects that Hibernate currently supports.
+
+[[GeneratedValues]]
+== Generated Values
+
+Previous versions of Hibernate silently ignored annotations `@GeneratedValue` applied to non identifier fields.
+
+E.g.
+
+```
+@Entity
+class Entity{
+
+    @Id
+    Integer id,
+
+
+
+    @GeneratedValue // Ignored in Hibernate versions < 6.4, since 6.4 an AnnotationException is thrown
+    String name;
+}
+
+```
+
+From 6.4 this mapping is not allowed anymore and an `AnnotationException` will be raised.