Hello,

as far as I know, when using Hibernate, data base accesses (SQL queries) are executed when arriving at the end of the Transaction code (in the Java source code). This corresponds to what I have observed when debugging.

Currently, in the Java code, I am deleting something from the database, then adding another object (actually to replace the former by the latter).
In the code, the delete operation is of course before the add one. However, that seems not to be the order of accesses in the database ==> the "former" object has not yet been deleted when the "latter" is attempted to be added to the DB. This results in an error b/c of an existing unique key constraint (the "latter" cannot be inserted since the "former", which at that time should no more be there, has its key).

To fix this, is there any way to influence the order of database access operations carried out by Hibernate? I.e. to ensure it deletes first, and inserts afterwards?
Or does the issue have another origin?

The order of SQL statements is documented here: http://docs.jboss.org/hibernate/core/3. ... e-flushing

I don't know about any way to change the order. Maybe you can put in clever calls to session.flush() after you have deleted the existing entity, but before the new entity is saved?

It was indeed the call to flush() - as also proposed in the German forum - right after the delete operation that resolved this issue.
(A call to remove(objectToBeRemoved) has to precede the flush()).