Marco Belladelli ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=637b480... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYWFkYWFlYjll... ) / Improvement ( https://hibernate.atlassian.net/browse/HHH-16313?atlOrigin=eyJpIjoiYWFkYW... ) HHH-16313 ( https://hibernate.atlassian.net/browse/HHH-16313?atlOrigin=eyJpIjoiYWFkYW... ) Throw an appropriate error when a mappedBy property references the wrong entity type ( https://hibernate.atlassian.net/browse/HHH-16313?atlOrigin=eyJpIjoiYWFkYW... ) Issue Type: Improvement Assignee: Marco Belladelli ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=637b480... ) Created: 15/Mar/2023 06:48 AM Priority: Major Reporter: Marco Belladelli ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=637b480... ) We have seen multiple cases of users migrating from Hibernate 5 to 6 getting errors caused by having an invalid mapping: entity collections annotated with a mappedBy which references a property of a different type of the original entity. For example: @Entity public static class EntityA { @Id private Long id; @OneToMany( mappedBy = "three" ) private List<EntityB> twos; } @Entity public static class EntityB { @Id private Long id; @ManyToOne private EntityC three; } @Entity public static class EntityC { @Id private Long id; } This type of mappings used to work in Hibernate 5 (with unexpected results), but in 6 it causes errors. We should check the mappedBy property type and give a give a more informative error message. ( https://hibernate.atlassian.net/browse/HHH-16313#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16313#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#100217- sha1:fd7c927 )