Christian Beikov ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiZTljNWI5MTQx... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16370?atlOrigin=eyJpIjoiZTljNW... ) HHH-16370 ( https://hibernate.atlassian.net/browse/HHH-16370?atlOrigin=eyJpIjoiZTljNW... ) Using MapKey on ManyToMany leads to wrong insert SQL ( https://hibernate.atlassian.net/browse/HHH-16370?atlOrigin=eyJpIjoiZTljNW... ) Issue Type: Bug Affects Versions: 6.2.0.CR4 Assignee: Unassigned Components: hibernate-core Created: 24/Mar/2023 12:02 PM Priority: Major Reporter: Christian Beikov ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) The model is: @Entity(name = "MapContainer" ) @Table(name = "map_container" ) public static class MapContainer { @Id private Long id; @ManyToMany @MapKey(name = "mapKey" ) private Map<MapKeyEntity, MapValueEntity> map = new HashMap<>(); public MapContainer() { } public MapContainer( Long id) { this.id = id; } } @Entity(name = "MapKeyEntity" ) @Table(name = "map_key_entity" ) public static class MapKeyEntity { @Id private Long id; public MapKeyEntity() { } public MapKeyEntity( Long id) { this.id = id; } } @Entity(name = "MapValueEntity" ) @Table(name = "map_value_entity" ) public static class MapValueEntity { @Id private Long id; @ManyToOne(optional = false ) private MapContainer mapContainer; @ManyToOne(optional = false ) @JoinColumn(unique = true ) private MapKeyEntity mapKey; public MapValueEntity() { } public MapValueEntity( Long id) { this.id = id; } } I don’t know if @MapKey makes sense here or what 5 did, but it worked before. ( https://hibernate.atlassian.net/browse/HHH-16370#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16370#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#100219- sha1:ac3e918 )