Christian Beikov ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiN2ZjY2MxOTY5... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-14017?atlOrigin=eyJpIjoiN2ZjY2... ) HHH-14017 ( https://hibernate.atlassian.net/browse/HHH-14017?atlOrigin=eyJpIjoiN2ZjY2... ) Adding PK proxy using field access to non-pk mapped collection results in NULL constraint violation ( https://hibernate.atlassian.net/browse/HHH-14017?atlOrigin=eyJpIjoiN2ZjY2... ) Issue Type: Bug Affects Versions: 5.4.14 Assignee: Unassigned Components: hibernate-core Created: 12/May/2020 13:00 PM Priority: Major Reporter: Christian Beikov ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) A simple model that maps a collection through a unique column @Entity @Table(name = "base_object" ) public class BaseObject implements Serializable { @Id @Column(name = "id" ) @GeneratedValue(strategy = GenerationType.AUTO) private Integer id; @Column(name = "name" , nullable = false , unique = true ) private String name; @ManyToMany @JoinTable( name = "related_objects" , joinColumns = @JoinColumn(name = "base_name" , referencedColumnName = "name" ), inverseJoinColumns = @JoinColumn(name = "related_name" , referencedColumnName = "name" ) ) private Set<RelatedObject> related = new HashSet<>(); } @Entity @Table(name = "related_object" ) public class RelatedObject { @Id @Column(name = "id" ) @GeneratedValue(strategy = GenerationType.AUTO) private Integer id; @Column(name = "name" , nullable = false , unique = true ) private String name; } When trying to add a RelatedObject reference to the collection, the flushing fails with a NULL constraint violation, although the proxy is lazily initialized. BaseObject b = entityManager.find(BaseObject.class, bId); RelatedObject r = entityManager.getReference(RelatedObject.class, rId); b.getRelated().add(r); entityManager.flush(); ( https://hibernate.atlassian.net/browse/HHH-14017#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-14017#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#100126- sha1:dd08494 )