高手帮看下,新手不会写SQL
SELECT A.ID,A.Name,
(SELECT COUNT(B.ID) FROM Doc_List B WHERE B.Doctype = A.ID AND B.PrjID=2) As DocCount
FROM Doc_Type A
Where (SELECT COUNT(B.ID) As DocCount FROM Doc_List B WHERE B.Doctype = A.ID AND B.PrjID=2)> 0
ORDER BY A.ID
这据SQL能执行,但感觉是不是重复了,效率低下,高手指教下应该怎么写!谢谢!
------解决方案--------------------select
A.ID,A.Name,COUNT(B.ID) as DocCount
from
Doc_Type A,
Doc_List B
where
B.Doctype = A.ID and B.PrjID=2
group by
A.ID,A.Name