删除所有值，然后单击一个

I have a table like:

我有一张桌子:

uid | name | user_id
--------------------
1   | aaa  | 111 
2   | bbb  | 111
3   | ccc  | 222
4   | aaa  | 222
5   | vvv  | 333
6   | zzz  | 333
7   | aaa  | 111
8   | bbb  | 111
uid | name | u