Every derived table must have its own alias

错误复现：

在写带有子查询或者在查询时产生临时表的查询时，可能会出现这个错误：

ERROR 1248 (42000): Every derived table must have its own alias

意思是「每一个派生出来的表都必须给它命名一个自己的别名」 

错误的sql示例： 

select dataid FROM (
select dataid ,if(dataid in (select ID from aip_1732602471460208641_file where ID in(1095884)),"yes","no")AS results from gf_file where aipId = 1732602471460208641 ) where results = 'no' Limit 1

错误原因：

执行这个sql时就会产生一张新的表，和前面的表联合查询

select dataid ,if(dataid in (select ID from aip_1732602471460208641_file where ID in(1095884)),"yes","no")AS results from gf_file where aipId = 1732602471460208641

但是mysql要求每一个派生出来的表都必须有一个自己的别名，那我给派生表加上别名即可；

eg：修改后的sql，直接在新生产的表中加入 他的别命名就行（“as a”或者“a”），“a”为新表的别名

select dataid FROM (
select dataid ,if(dataid in (select ID from aip_1732602471460208641_file where ID in(1095884)),"yes","no")AS results from gf_file where aipId = 1732602471460208641 ) AS a  where results = 'no' Limit 1