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回复 1# bzh_516
先生成数据吧,然后再回导就可以了:- mysql> set @last_id := -1;
- set @new_session_id := -1;
- select id, new_session_id, name
- from
- (
- select *, @new_session_id := ifnull(session_id, @last_id) as new_session_id, @last_id := @new_session_id
- from tbtest
- ) as tmp;
- Query OK, 0 rows affected
- Query OK, 0 rows affected
- +----+----------------+------+
- | id | new_session_id | name |
- +----+----------------+------+
- | 1 | 1 | 张三 |
- | 2 | 1 | 张三 |
- | 3 | 2 | 张三 |
- | 4 | 2 | 张三 |
- | 5 | 2 | 张三 |
- | 6 | 3 | 张三 |
- | 7 | 3 | 张三 |
- | 8 | 3 | 张三 |
- | 9 | 3 | 张三 |
- | 10 | 3 | 张三 |
- | 11 | 4 | 张三 |
- | 12 | 4 | 张三 |
- +----+----------------+------+
- 12 rows in set
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