[SOLVED] Stuck on SQL Query

[Petty_Crim]

I'm stuck on this sql query that gets a list of users that can be made into moderators. I got a database with a table called category_moderators, which has two fields category_id and user_id. I'm making a drop down list of available users that can be made into moderators, but I only want to display users who are currently not a moderator for that particular category.

 

This is my query I'm using atm:

$get_moderators=mysql_query("SELECT users.user_id, users.user_name FROM users, category_moderators WHERE (category_moderators.category_id='$chosen_category_id' AND users.user_id!=category_moderators.user_id)")

 

Before this query is run the user picks the category they want to add the moderator to as such if they pick say category 1 then the query should exclude listing users that are moderators in category 1.

[rajivgonsalves]

try the <> instead of the !=

[Petty_Crim]

try the <> instead of the !=

Nope still doesn't work.

[bache]

SELECT u.user_id, u.user_name FROM users u
WHERE    not exists
(select 1 from category_moderators cm
	where cm.category_id = $chosen_category_id
	and u.user_id = cm.user_id

[Petty_Crim]

SELECT u.user_id, u.user_name FROM users u
WHERE    not exists
(select 1 from category_moderators cm
	where cm.category_id = $chosen_category_id
	and u.user_id = cm.user_id

Thx that seemed to do the trick.