Koen Serneels ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYjhjYzllNTRm... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-14054?atlOrigin=eyJpIjoiYjhjYz... ) HHH-14054 ( https://hibernate.atlassian.net/browse/HHH-14054?atlOrigin=eyJpIjoiYjhjYz... ) Hibernate insert/update ordering wrt unique constraints ( https://hibernate.atlassian.net/browse/HHH-14054?atlOrigin=eyJpIjoiYjhjYz... ) Issue Type: Bug Affects Versions: 5.4.17 Assignee: Unassigned Components: hibernate-core Created: 02/Jun/2020 00:05 AM Priority: Major Reporter: Koen Serneels ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) Hi. In the example created for this question (please see: https://github.com/koen-serneels/hibernate-uc-violation ) is an entity with a single property ‘value’ and unique constraint. Initially there is an existing instance with it’s property ‘value’ equal to ‘val1’. When we now do following within the same transaction: * change the value on the existing entity from “val1” to “val2” * add a new entity with “val1” We get a ConstraintViolationException because Hibernate is executing the insert before the update. Two questions about this behavior * Is this actually expected knowing that Hibernate knows about the unique constraint and that it would make more sense to perform the insert after the update? * Is there a more elegant way to deal with this than performing manual flushes as illustrated by the test case? Btw; I posted this first on the forum ( https://discourse.hibernate.org/t/hibernate-insert-update-ordering-wrt-un... , but in absence of any response I started thinking this might be a bug. Thanks! ( https://hibernate.atlassian.net/browse/HHH-14054#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-14054#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#100127- sha1:6728f9f )