[hibernate-issues] [JIRA] (HHH-16054) JPA / Hibernate, duplicate pkey error when updating entity that is a subclass of a base class that uses IdClass for composite primary key

Cui Pengfei ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiY2I3NTA4MGY0... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16054?atlOrigin=eyJpIjoiY2I3NT... ) HHH-16054 ( https://hibernate.atlassian.net/browse/HHH-16054?atlOrigin=eyJpIjoiY2I3NT... ) JPA / Hibernate, duplicate pkey error when updating entity that is a subclass of a base class that uses IdClass for composite primary key ( https://hibernate.atlassian.net/browse/HHH-16054?atlOrigin=eyJpIjoiY2I3NT... ) Issue Type: Bug Affects Versions: 5.6.14 Assignee: Unassigned Components: hibernate-core Created: 17/Jan/2023 06:12 AM Environment: Hibernate libraries: hibernate-core-5.6.14.Final.jar hibernate-commons-annotations-5.1.2.Final.jar JVM: openjdk 16 operating system, mac 12.6.2 and windows 10 database platform pg and mysql Priority: Major Reporter: Cui Pengfei ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *************************** How to reproduce this issue *************************** https://github.com/cuipengfei/Spikes/tree/master/jpa/ClassIdUpdateIssue ( https://github.com/cuipengfei/Spikes/tree/master/jpa/ClassIdUpdateIssue ) this code can reproduce the issue, just run the main method then the error will happen. ***************** Issue Description ***************** There is a base class like this: @Entity @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorFormula( " case when vip_number is not null then 'vip' else 'normal' end" ) @DiscriminatorValue( "normal" ) @IdClass(CustomerPK.class) public class CustomerWithIdClass implements Serializable { private String firstName; private String lastName; @Id private Long versionId; @Id private Long unitId; protected CustomerWithIdClass() { } // getter and setters ...... } Its IdClass is like this: @NoArgsConstructor @EqualsAndHashCode @Embeddable public class CustomerPK implements Serializable { private Long unitId; private Long versionId; public void setUnitId( Long unitId) { this.unitId = unitId; } public void setVersionId( Long versionId) { this.versionId = versionId; } } Then it has a subclass: @Entity @DiscriminatorValue( "vip" ) public class VipCustomerWithIdClass extends CustomerWithIdClass { private String vipNumber; public VipCustomerWithIdClass() { } public VipCustomerWithIdClass( String firstName, String lastName, String vipNumber) { super (firstName, lastName); this.vipNumber = vipNumber; } public String getVipNumber() { return vipNumber; } public void setVipNumber( String vipNumber) { this.vipNumber = vipNumber; } } The subclass only adds one additional field, nothing else fancy. Then when I try to persist an instance of the subclass like this: CustomerWithIdClass customer = new CustomerWithIdClass( "a" , "b" ); customer.setVersionId(123L); customer.setUnitId(456L); repository.save(customer); //save object of base class, ok customer.setFirstName( "a2" ); repository.save(customer); //modify object of base class and save again, ok VipCustomerWithIdClass vipCustomer = new VipCustomerWithIdClass( "a" , "b" , "888" ); vipCustomer.setVersionId(987L); vipCustomer.setUnitId(654L); repository.save(vipCustomer); //save object of subclass, ok vipCustomer.setVipNumber( "999" ); repository.save(vipCustomer); //modify object of subclass and save again, NOT OK // ↑ THIS FAILS BECAUSE OF PRIMARY KEY CONFLICT. INSERT STATEMENT WAS USED INSTEAD OF UPDATE, WHY? // this failure only happens when: // 1. base class uses IdClass for composite primary key // 2. saving an instance of the subclass for the second time after modification ********* The Error ********* Then there will be an *error of duplicate pkey* when I try to save the instance of the *subclass* for the *second time* *after some modification*. The error seems to be related with the @ *IdClass* annotation, because I have tried using @ *EmbeddedId* and @ *Embeddable* for composite pkey, then the error does not happen. ************ The question ************ What is the root reason of this issue? Is @IdClass not supposed to be used for this scenario? ***** links ***** https://stackoverflow.com/questions/75147518/jpa-hibernate-duplicate-pkey... ( https://stackoverflow.com/questions/75147518/jpa-hibernate-duplicate-pkey... ) ( https://hibernate.atlassian.net/browse/HHH-16054#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16054#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#100214- sha1:771690a )