sql commands

I am trying to debug a pg database that was set up under pg 7.0.3 and am
now trying to run it for testing on a local FreeBSD machine under pgsql
7.2.1_1 and php4.1.2 module and apache1.3 something. All is set up
correctly, but the rebuilt database is giving some problems.
I note that there are sql commands in the php files: sqlconnect, sqlget,
select - I don't quite understand how these commands fit in with php. Has
something changed in the newer version of php4?
I do not find any reference to the sql commands in the handbook.
I would much appreciate some help on this as I am quite new to php.
Philip Jourdan