我的数据库看起来像这样,在用户,userteam(连接表)和车队指令:选择所有用户谁不是在一个团队
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 | +--------+-------+
+--------+--------+
如何选择,在是不是所有用户一个团队,并只回声一次?我试着与用户表做,但随后会响应举例来说,如果我尝试和选择所有成员不在队以3:
SELECT userid FROM userteam WHERE teamid!=3;
SELECT * FROM user WHERE userid='$previousSql';
1 eric
1 eric
2 john
3 carl
想我的却是:
1 eric
2 john
3 carl
我正在添加成员函数,我非常不喜欢每个人都出现多次..任何方向,帮助或指导将不胜感激。
请在查询添加组例如SELECT * FROM user WHERE userid ='$ previousSql'group by name; –