Sql語句優化

in修改爲exists

一：in

hql +=" and b.newsid  in (select f.object from FeedBack f where f.type=1 and f.operate=1 and f.userid in (select u.userid from SysUser u where f.userid = u.userid and u.username like '%"+filterValue+"%'))";

 

二：exist

hql +=" and exists (select f.object from FeedBack f where b.newsid = f.objectid and f.type=1 and f.operate=1 and exists (select u.userid from SysUser u where f.userid = u.userid and u.username like '%"+filterValue+"%'))";

第一個：select u.userid from SysUser u where f.userid = u.userid and u.username like '%"+filterValue+"%'；

第二個：select f.object from FeedBack f where b.newsid = f.objectid and f.type=1 and f.operate=1

第三個：select b from PreNewsTips  b where 1=1 ;

三：

hql += "select max(n.orders) from NewsIssueClassify n where parentid=?";