求优化这个SQL运行时间,现在是17秒
select * from 基本信息表1 left join (select * from 基本沟通表1 where Gid IN (select Max(Gid) from 基本沟通表1 group by 基本沟通表1.Qid)) as t2 on 基本信息表1.id =t2.Qid where 1=1
and t2.求职状态='情况不明'
------解决方案--------------------执行计划贴出来
------解决方案--------------------select * from 基本信息表1 left join
(select t3.* from 基本沟通表1 t3 inner join (select Max(Gid) from 基本沟通表1 group by 基本沟通表1.Qid) t4
on t3.gid=t4.gid and t3.qid=t4.qid) t2
on 基本信息表1.id =t2.Qid
where 1=1 and t2.求职状态='情况不明'
------解决方案--------------------应该用inner join
试试我这句要多久
select * from 基本信息表1 a inner 基本沟通表1 b
on a.id=b.qid
and b.求职状态='情况不明'
and not exists (select c.gid from 基本沟通表1 c on c.qid=b.qid and c.Gid>b.Gid)