Querying for specific users based on values fields

I want to run a query on my users to return all the users who have a field populated, along the lines of:

"SELECT name, cb_ukclimbingid FROM #_comprofiler WHERE cb_ukclimbingid is NOT NULL"

I would then loop through the list returned using the cb_ukclimbingid value to query and return an array of climbs people have undertaken (I can do this bit).

I have had a search of the forums & Kyles tutorials ( www.allmysocials.com/directory/tutorials ) but can't seem to see anything that helps me.

Any advice or pointers where to look?