beginners questions

[Didju_Juzphart]

Hey there, I'm a long time lurker, 1st time poster.

Despite being an inexperienced coder I thought I'd have a crack at creating my very own mod for the zencart community. However, I've come up against first hurdle.

I thought I understood simple SQL but having a look at category_tree.php I can't figure out why
c.categories_id
ptc.category_id

have c. and ptc. in-front of them. Are they alias or something?

Where did they come from?

Sorry for being a noob, looked through SQL manuals but can't spot why

thanks :)

[gjh42]

Yes, those are abbreviations for the table names.

If you look at the beginning of that select, you will find something like
categories c
or
TABLE_CATEGORIES . ' c
which is the assignment.

[Didju_Juzphart]

thank you very much :)