DBUnit automatic dataset generation
You could use a database mock data generator to feed your database and then dump the table content with DBUnit. I have experience with dbMonster and databene benerator (see this previous answer).
I would actually recommend the later in your case because it can create database snapshots directly in DbUnit format. There is an Eclipse plugin but sadly nothing for NetBeans AFAIK.
UPD. 2016: The eclipse plugin is discontinued.