Testing strategies for PHP when you have no original function [on hold]

I'm teaching myself PHP, wondering if I could ask for some advice about testing.

I'm almost done with my first website, but I noticed that I didn't make original functions. I used PHP mainly for accessing MySQL. Instead, (I used JavaScript in terms of functionalities.)

In such a case, what do you think is a reasonable testing strategy?

• I'd like to ensure that accessing MySQL always works properly, but the connectivity could be tested by writing some PHP script in such a way.
• PHP Unit can be used for unit testing, but I don't think this could be useful for this time, since I didn't make functions in PHP.
• I saw this posting and found PHP_CodeSniffer cool, so I'm going to give it a try. However, it's not to do with MySQL. (Plus, I'm struggling from running it...)

Any advice would be appreciated. I hope this posting would benefit others who began to learn PHP.