日期:2014-05-18  浏览次数:20520 次

问下,这个SQL语句应该怎么优化
select * from 
(
  select * from tb1 
)
left join
(
 select * from tb2
)
where .....

------解决方案--------------------
SQL code

select * from tbl a left join tb2 b on a.col=b.col
where ......

------解决方案--------------------
select * from tb1
left join tb2 on ....
where .....
------解决方案--------------------
select * 
from tb1
left join tb2 on ...
where ...