选择不在团队中的所有用户

Question

My database looks something like this, in order of user, userteam (connection table) and team:

    Usertable              UserTeam              Teamtable
+--------+------+    +--------+--------+    +--------+-------+
| userid | name |    | userid | teamid |    | teamid | name  |
+--------+------+    +--------+--------+    +--------+-------+
| 1      | eric |    | 1      |      1 |    |      1 | awsm  |
| 2      | john |    | 1      |      2 |    |      2 | doe   |   
| 3      | carl |    | 2      |      1 |    |      3 | empty |
+--------+------+    | 3      |      1 |    +--------+-------+
                     +--------+--------+

How do I select all users that IS NOT in a team, and echo them out only once? I've tried doing it with the usertable, but then it will echo for instance, if I try and select all members not in team 3:

SELECT userid FROM userteam WHERE teamid!=3;
SELECT * FROM user WHERE userid='$previousSql';

1 eric
1 eric
2 john
3 carl

What I'd like instead is:

1 eric
2 john
3 carl

I'm making an add members function, and I'd very much not like everyone to show up more than once.. Any directions, help or guiding would be much appreciated.

Answer 1

This should do it:

SELECT u.userid, u.name FROM Usertable u
INNER JOIN UserTeam ut ON ut.userid = u.userid
INNER JOIN Teamtable tt ON tt.teamid = ut.teamid
WHERE tt.teamid != 3
GROUP BY u.userid, u.name;