Connecting to mysql with ssh in php 5.2

We are currently developing php in eclipse.
I'm having trouble because I don't know how to connect to mysql in ssh in php5.2.

If you include ss2_connect in the source, you will find ss2.php in the language library and
If you do this, you will receive an error stating that there is no definition of ss2_connect.

I don't know why the ss2_connect function exists in ss2.php, but there is no definition.

If anyone understands, please let me know.