删除全部数据，但保留最后添加的10条，SQL语句怎么写？在线等！

[mfkiqpl]

RT，
删除一个表的全部数据，仅保留最后添加的10条。
求个SQL。。
这样写行不通：
delete from `onlist` where `id` not in (select `id` from `onlist` order by `id` desc limit 10)

[青锋-SS]

delete from onlist where id not in (select TOP 10 id from onlist order by id desc)

[青锋-SS]

delete from onlist where id not in (select TOP 10 id from onlist order by id desc)
不过这是ms sql的写法不知道是否适合你的情况

[mfkiqpl]

谢谢楼上两位。。但我要的是MYSQL。。MYSQL里不能用TOP

[懒得去死]

MYSQL暂时不支持子查询中引用自己的字段。

不过有折中的方案：


mysql> select * from table_a;
+----+-----------+------+
| id | parent_id | name |
+----+-----------+------+
| 0 | -1 | - |
| 1 | 0 | a |
| 2 | 1 | b |
| 3 | 1 | c |
| 4 | 1 | d |
| 5 | 2 | e |
| 6 | 2 | f |
| 7 | 3 | g |
| 8 | 4 | h |
| 9 | 6 | i |
| 10 | 8 | j |
| 11 | 9 | k |
| 12 | 11 | l |
+----+-----------+------+
13 rows in set (0.00 sec)

mysql> create temporary table tmp select * from table_a order by id desc limit 1
0;
Query OK, 10 rows affected (0.16 sec)
Records: 10 Duplicates: 0 Warnings: 0

mysql> truncate table table_a;
Query OK, 13 rows affected (0.08 sec)

mysql> insert into table_a select * from tmp;
Query OK, 10 rows affected (0.05 sec)
Records: 10 Duplicates: 0 Warnings: 0

mysql> select * from table_a;
+----+-----------+------+
| id | parent_id | name |
+----+-----------+------+
| 3 | 1 | c |
| 4 | 1 | d |
| 5 | 2 | e |
| 6 | 2 | f |
| 7 | 3 | g |
| 8 | 4 | h |
| 9 | 6 | i |
| 10 | 8 | j |
| 11 | 9 | k |
| 12 | 11 | l |
+----+-----------+------+
10 rows in set (0.00 sec)

mysql>

[青锋-SS]

没有类似的语句,就像你写的limit

[青锋-SS]

?

[mfkiqpl]

谢谢：yueliangdao0608
你的是建临时表，如果没有更好的办法，就只有用你这个办法了。。

再等等看有没有更好的办法。。


回：sdhylj(青锋-SS)
与TOP类似的写法就是limit 。但子查询里不能用 limit

[mfkiqpl]

不等了。。谢谢： yueliangdao0608

结贴了

[青锋-SS]

谢谢楼主,多了个角角