时间：2022-03-13 12:55:18 | 栏目：Mysql | 点击：次
表relation
create table relation( id int primary key auto_increment, userId int not null, fanId int not null );
插入几条数据
insert into relation(userId,fanId) values(1,1) ,(1,1) ,(1,1), (2,2),(2,2) ,(3,3),(3,3);
表中的数据
| id | userId | fanId |
|---|---|---|
| 1 | 1 | 1 |
| 2 | 1 | 1 |
| 3 | 1 | 1 |
| 4 | 2 | 2 |
| 5 | 2 | 2 |
| 6 | 3 | 3 |
| 7 | 3 | 3 |
去重
delete t from relation s join relation t using(userId,fanId) where s.id<t.id;
总结