SQL delete query

[ZiNgA BuRgA]

You may wish to look into reading a bit about database design.  In general, everything needs to have a primary key, and it's typically an autoincremented number (id).  Examples in MyBB: user ID (uid), thread ID (tid) etc.  Note that these IDs uniquely identify any user or thread object.

Your switch statement is better as it prevents the user from putting whatever they want in that query, although now you have voodoo numbers (eg, why 1 or 2?).