Hibernate - how to catch "integrity constraint violation: unique constraint or index violation"

Question

In my table I have a unique constraint. In hibernate, when I add an item that violates that constraint, I want to catch it, so It will update instead of create an item.

When I set no try-catch block around

    updated = query.executeUpdate();

it gets following error

    Caused by: org.hsqldb.HsqlException: integrity constraint violation: unique constraint or index violation: WEEKROOSTERITEMUNI

When I set the following try-catch block

    try {
        updated = query.executeUpdate();

     }    
   catch(PersistenceException e){                                                         
        LOG.debug("this is PersistenceException exception throw");      
    } 

it gets the following error

    Caused by: javax.persistence.RollbackException: Transaction marked as rollbackOnly

When I catch "ConstraintViolationException" I just keep getting the constraint exception, it doesn't catch anything.

    Caused by: org.hsqldb.HsqlException: integrity constraint violation: unique constraint or index violation: WEEKROOSTERITEMUNI

How can I catch this?

Answer 1

The RollbackException is thrown at a higher level because @Transactional is set in that higher lever, so you can't catch it on that level. You need to catch it in the layer of your transaction.

A better way is to do a check if the object already exists on the database layer. A check-function. That check function is a get by the unique constraints. This is better because you don't need to catch exceptions.

You already need that get-function of the object, because you later want to merge that object. You don't want to merge a detached instance.