这个sql语句怎么写,急
SELECT p.ProjectID,p.ProjectCode,p.ProjectName,
Total_Amt = CASE p.Amt_Revised WHEN 0 THEN p.Amt_Original ELSE p.Amt_Revised END ,
(CASE p.Amt_Revised WHEN 0 THEN p.Amt_Original ELSE p.Amt_Revised END-a.Collected) NotCollected
FROM tbProject p,(
SELECT SUM(PaymentCollected) Collected,ProjectID
FROM tbFinanceItem
GROUP BY ProjectID)a
WHERE p.ProjectID=a.ProjectID AND p.ProjectStatus=1
然后有可能某个p.ProjectID在tbFinanceItem表中还无数据,这时也要显示,并把NotCollected 设为为p.Amt_Original. 这该怎么写呢?