Canceling Records

[dbchip2000]

Hi,
I am trying to write a script that will query a user table to find all users who are not in mapped in a group member table.

users have (id, username, password)
groups have (id, title)
groups_members have (id, group_id, user_id)

So I want to select the users who are found in a group member such as 'SELECT * FROM groups_members, users WHERE groups_members.user_id=users.id AND groups_members.group_id=2' and then kind of cancel out the found users to get a list of groups_members.user_id who aren't in the group.

Am I kind of making sense? Thanks for the ideas

[alanzhao]

SELECT group_memebers.user_id FROM group_members, groups WHERE groups.id!=group_members.group_id

just trying to help.😕

[jayant]

a LEFT JOIN will do it

http://www.mysql.com/doc/en/JOIN.html
http://www.mysql.com/doc/en/LEFT_JOIN_optimisation.html