Sometimes I need to transfer data from my remote database (product/test) to my local box. I usually use dbUnit to avoid the transfer. However, sometimes I need to use specific data to solve either a specific bug. If you are using MySQL, then most likely you are using mysqldump. It's a really good tool. Here is how I transfer data from my test environment (marcelo.prod) to my local box without affecting (delte, truncate, or doing anything to my current schema):
mysqldump -h marcelo.prod -uprod_username -pprod_password --skip-create-options --no-create-info --no-create-db --compact --skip-add-drop-database --insert-ignore --where="OPERATOR_SERVICE = 'MBLOX_US'" upmobile OPERATOR_TBL | mysql -uroot -psecret upmobile
I also use this code to transfer data from my production database to my historic database.