id user content
1 aaa test
2 aaa test1
3 bbb test2
4 aaa test3
5 ccc test4
6 bbb test5
7 bbb test6
如上表,需要查询数据。常规写法是 select * from table order by id desc现有个需求,user字段,一个用户名只显示一条最新的。语句该如何写呀?
1 aaa test
2 aaa test1
3 bbb test2
4 aaa test3
5 ccc test4
6 bbb test5
7 bbb test6
如上表,需要查询数据。常规写法是 select * from table order by id desc现有个需求,user字段,一个用户名只显示一条最新的。语句该如何写呀?
from tb A
where not exists (select 1 from tb where A.user=B.user and A.id>id)
+------+------+---------+
| id | user | content |
+------+------+---------+
| 4 | aaa | test3 |
| 5 | ccc | test4 |
| 7 | bbb | test6 |
+------+------+---------+
3 rows in set (0.00 sec)
这样?
请楼下斧正
[征集]分组取最大N条记录方法征集,及散分....