Every derived table must have its o
在mysql查询中遇到的一个问题,产生的一个错误Every derived table must have its own alias ,涉及到mysql的order by查询和group by 查询.
需求是这样的,想查询表中的每个用户下的最新的记录,既有orderby 又有groupby,总是查询不成功.
开始写的语句是这样的
$sql="select * from table order by logid desc ,group by userid";查询总是错误的
错误如下:MySQL server version for the right syntax to use near 'order by c_position_id desc,group by c_id'不能直接用order by 和group by.
更改如下:http://%77%77%77%2E%66%6F%72%61%73%70%2E%63%6E
select * from (select * from table order by logid desc) group by userid desc;
这样的查询便出来上面的错误:Every derived table must have its own alias
查询网络得到答案.
如果有表中的子表格,那么要进行as 重命名,如果不重名则出现Every derived table must have its own alias 的错误
更改如下:
select * from (select * from table order by logid desc) as table1 group by userid desc;
as的表名可以根据自己的需要命名.
运行成功,问题解决.