SQL從兩個表中的查詢匹配條件中刪除？

Question

所有行都得到與此查詢刪除，而我只是想刪除這些行，其中measureid匹配下面兩個表中：

delete from temp1 
where exists (select t1.* 
       from temp1 t1, temp2 t2 
       where t2.measureid = t1.measureid) 

我有什麼改變？

Answer 1

我不認爲你想使用exists我想你想使用in

delete from temp1 where measureid in 
    (select t1.measureid from temp1 t1, temp2 t2 where t2.measureid = t1.measureid); 

或更好，但

delete from temp1 where measureid in 
    (select measureid from temp2); 

Answer 2

這是因爲

select t1.* from temp1 t1, temp2 t2 where t2.measureid = t1.measureid 

總是返回行。你可能想要的是

delete from temp1 t1 where exists (select t2.* from temp2 t2 where t2.measureid = t1.measureid)