sql - sql查询获得ID明智的平衡

Question

我有以下 SQL 查询：（Oracle 10）

SELECT
     A.ID,
     SUM(A.AMT_CR) - SUM(A.AMT_DR) AS balAmt,
     P.NAME
FROM TABLE1 A, TABLE2 P
WHERE P.ID BETWEEN 'C0100' AND 'C0200'
    AND P.ID = A.ID
    AND A.TRANS_DATE < '01-FEB-2013'
GROUP BY A.ID, P.NAME
ORDER BY A.ID

上面的查询执行得很好，但是这个查询有一个条件AND A.TRANS_DATE < '01-FEB-2013'。这个条件是为了balAmt在TRANS_DATE. 但是这个查询的问题是它只得到IDs相对于AND A.TRANS_DATE < '01-FEB-2013'条件的。如果 aID不TRANS_DATE小于，'01-FEB-2013'则不会显示 that 的记录ID。

所以我想IDs从数据库中获取所有。但我想得到balAmt条件AND A.TRANS_DATE < '01-FEB-2013'..

任何建议将不胜感激。

提前致谢。

Answer 1

SELECT Q.ID, W.balmt, W.NAME
FROM TABLE1 Q
LEFT JOIN (
SELECT
     A.ID,
     SUM(A.AMT_CR) - SUM(A.AMT_DR) AS balAmt,
     P.NAME
FROM TABLE1 A, TABLE2 P
WHERE P.ID BETWEEN 'C0100' AND 'C0200'
    AND P.ID = A.ID
    AND A.TRANS_DATE < '01-FEB-2013'
GROUP BY A.ID, P.NAME
) W
ON Q.ID = W.ID
ORDER BY A.ID

Answer 2

SELECT
     A.ID,
     SUM(case when A.TRANS_DATE < '01-FEB-2013' 
         then nvl(A.AMT_CR,0) - nvl(A.AMT_DR,0)
         else 0
         end) AS balAmt,
     P.NAME
FROM TABLE1 A, TABLE2 P
WHERE P.ID BETWEEN 'C0100' AND 'C0200'
    AND P.ID = A.ID
GROUP BY A.ID, P.NAME
ORDER BY A.ID

Answer 3

这应该这样做：

SELECT
     A.ID,
     SUM(A.AMT_CR) - SUM(A.AMT_DR) AS balAmt,
     P.NAME
FROM TABLE1 A
LEFT JOIN TABLE2 P ON P.ID = A.ID
                   AND A.TRANS_DATE < '01-FEB-2013'
                   AND P.ID BETWEEN 'C0100' AND 'C0200'
GROUP BY A.ID, P.NAME
ORDER BY A.ID