multiple queries using PHP

My original problem began with.. I have a category table
cat_id (unique id)
cat_title (category title)
mastercat (0 indicates a main category, otherwise points to another cat_id
which indicates this category to be a subcategory)

I want to select cat_id and cat_title where mastercat=0
and at the same time would like to know whether these categories have any
other categories assigned to them via the mastercat.

I thought possibly my solution would be to select cat_id, cat_title into
temporary table where mastercat=0

then continue from there somehow.

Which lead me to my next question, which was how could I execute multiple
queries from within PHP ?

--------------------------------------------------------------------
Kevin Heflin | ShreveNet, Inc. | Ph:318.222.2638 x103
VP/Production | 333 Texas St #175 | FAX:318.221.6612
kheflin(at)shreve(dot)net | Shreveport, LA 71101 | http://www.shreve.net
--------------------------------------------------------------------