Marco Belladelli ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=637b480... ) *commented* on HHH-16855 ( https://hibernate.atlassian.net/browse/HHH-16855?atlOrigin=eyJpIjoiNzg2Nj... ) Re: With IdClass if parts of composite key is auto generated, while saving PropertyAccessException thrown ( https://hibernate.atlassian.net/browse/HHH-16855?atlOrigin=eyJpIjoiNzg2Nj... ) On-execution generated values, like the GenerationType.IDENTITY strategy, are not supported for composite identifiers. I did a quick test and even in Hibernate 5 this caused an exception. A better error message will be introduced in Hibernate 6.3 thanks to the change in https://hibernate.atlassian.net/browse/HHH-16692. ( https://hibernate.atlassian.net/browse/HHH-16855#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16855#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#100228- sha1:4a42edc )