Help with this small script (MYSQL) (Help running a query)

[Slybone]

Let me explain how our system works, you cannot register on the forums, the only way to get an account on the forums is to have an account on outwar, since outwar has 3 playing servers. www, torax, and fabar we need to change the way it gives people userID's & names
If a user on www has the username vBulletin and their ID is 5
and a user on Torax has the username vBulletin and their ID is 1
then It would end up having 2 different ID's but the same name, thus screwing the DB
or...if a user has the same ID but different names then it will just delete the old user
so users on the www server keep thier regular id
torax users get +100000000
and fabar users get +200000000
to stop this from happening, this hasnt caused any issues.
and to answer your first question im not sure if the table in users already exsits before it runs the query, It should...