Hibernate Delete Error: Batch Update Returned Unexpected Row Count

The error can be caused by several things. I'm not taking the credit for it, found it here.

1. Flushing the data before committing the object may lead to clear all object pending for persist.
2. If object has primary key which is auto generated and you are forcing an assigned key
3. if you are cleaning the object before committing the object to database.
4. Zero or Incorrect ID: If you set the ID to zero or something else, Hibernate will try to update instead of insert.
5. Object is Stale: Hibernate caches objects from the session. If the object was modified, and Hibernate doesn’t know about it, it will throw this exception — note the StaleStateException

Also look at this answer by beny23 which gives a few further hints to find the problem.

• In your hibernate configuration, set hibernate.show_sql to true. This should show you the SQL that is executed and causes the problem.
• Set the log levels for Spring and Hibernate to DEBUG, again this will give you a better idea as to which line causes the problem.
• Create a unit test which replicates the problem without configuring a transaction manager in Spring. This should give you a better idea of the offending line of code.

The exception org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1 use to be thrown when Hibernate notice that the entity he wants to flush to the database isn't exactly as it was at the beginning of the transaction.

I described more in details two different use cases that happen to me here.