select sum(t1.sales) from Store_information t1
where t1.store_name
IN （Select Store_name from Geography t2 where t2.store_name = t1.store_name）
以上sql文一运行就报错，有没有高手给解答一下是什么原因？
------解决方案--------------------
你难道没看出来你的条件矛盾了吗？
不知道你的需求，猜测一下。
- SQL code
select sum(t1.sales) from Store_information t1,Geography t2 where t1.store_name = t2.store_name;
------解决方案--------------------
select sum(t1.sales) from Store_information t1
where t1.store_name
IN （Select Store_name from Geography t2 ，Store_information t1 where t2.store_name = t1.store_name）
------解决方案--------------------
LZ贴下错误吧，表示没看出来错误在哪。
- SQL code
select sum(t.operid) from operskill t where t.skillid in ( select skillid from skillinfo t1 where t.skillid =t1.skillid);
------解决方案--------------------
- SQL code
--別用in，效率低select sum(t1.sales) from Store_information t1 where exists (Select 1 from Geography t2 where t2.store_name = t1.store_name);