But my partner accidentally(>_<) change my work and now it has an error…
So, before sorting out the problem with you SQL connection sort our the problem of owning your code. You're not really own it, because you can mess it up any minute. My advice is: stop doing what you're doing and start working under
Revision Control System. It's easy, inexpensive it terms of required resource and free of charge (if you make a right decision and use Open Source system; don't risk your valuable code asserts by trusting a proprietary code: they support it today but tomorrow may disappear from the market).
See this discussion:
Revision control systems, which to choose from?[
^] in general and my solution in particular.
Good luck,
—SA