Eduardo Simioni ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiOGE2OTQyYzAy... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-14129?atlOrigin=eyJpIjoiOGE2OT... ) HHH-14129 ( https://hibernate.atlassian.net/browse/HHH-14129?atlOrigin=eyJpIjoiOGE2OT... ) Bidirectional relationship fails to save after updating to 5.4.17 ( https://hibernate.atlassian.net/browse/HHH-14129?atlOrigin=eyJpIjoiOGE2OT... ) Issue Type: Bug Affects Versions: 5.4.17 Assignee: Unassigned Components: hibernate-core Created: 30/Jul/2020 14:38 PM Environment: H2 Database in MySQL mode was used for the test Priority: Major Reporter: Eduardo Simioni ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) After updating from 5.4.16 to 5.4.17 we had several unit tests failing in one of our projects. I did some investigation and came up with a minimum scenario and test case that reproduces the problem: @Entity public class Child { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @NotNull @ManyToOne private Parent parent; public void setParent(Parent parent) { this.parent = parent; } } @Entity public class Parent { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @ManyToOne(cascade = CascadeType.ALL) private Child child; public Parent(Child child) { this.child = child; this.child.setParent( this ); } public Child getChild() { return child; } } And a test case: @ExtendWith(SpringExtension.class) public class ParentChildTest { @Test @Transactional public void save() { Parent parent = new Parent( new Child()); sessionFactory.getCurrentSession().save(parent); sessionFactory.getCurrentSession().setHibernateFlushMode(FlushMode.MANUAL); sessionFactory.getCurrentSession().flush(); } @Resource private SessionFactory sessionFactory; } With 5.4.16 the following statements are executed and the test completes successfully insert into parent (id, child_id) values ( null , ?) insert into child (id, parent_id) values ( null , ?) update parent set child_id=? where id=? With 5.4.17 the result is DEBUG [SQL] insert into child (id, parent_id) values (null, ?) WARN [SqlExceptionHelper] SQL Error: 23502, SQLState: 23502 ERROR [SqlExceptionHelper] NULL not allowed for column "PARENT_ID"; SQL statement: insert into child (id, parent_id) values (null, ?) [23502-200] If the @NotNulll annotation is removed the entities are saved without any problem, only in a different order insert into child (id, parent_id) values ( null , ?) insert into parent (id, child_id) values ( null , ?) update child set parent_id=? where id=? It seems to be related with the fix provided by HHH-10956 ( https://hibernate.atlassian.net/browse/HHH-10956 ) Closed ( https://hibernate.atlassian.net/browse/HHH-14129#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-14129#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100140- sha1:5beb332 )