Question

表A

ITEM BASE_WT BASE_AMT
AAA 50 500
BBB 100 6000

表B

ITEM OUTDAY WT AMT
AAA 20140105 10 100
BBB 20140106 10 600
AAA 20140107 10 100

表A结果

AAA 30 300
BBB 90 5400

MSSQL QUERY

UPDATE A SET
BASE_WT  = BASE_WT - X.WT
BASE_AMT  = BASE_AMT - X.AMT
FROM A,
(
    SELECT ITEM , SUM(B.WT) WT, SUM(B.AMT) AMT 
    FROM B
    WHERE OUTDAY BETWEEN '20140105' AND '20140107'
    GROUP BY ITEM
) X
WHERE A.ITEM = X.ITEM

Answer 1

试试这个：

UPDATE A
SET (BASE_WT, BASE_AMT)
  = (SELECT A.BASE_WT - SUM(B.WT), A.BASE_AMT - SUM(B.AMT)
     FROM B
     WHERE B.OUTDAY BETWEEN '20140105' AND '20140107'
      AND B.ITEM = A.ITEM)
WHERE A.ITEM IN (SELECT ITEM FROM B WHERE OUTDAY BETWEEN '20140105' AND '20140107');

外部WHERE条件避免重置（为NULL）A中在子查询中没有相应ITEM的记录。

Answer 2

update a
  set (base_wt, base_amt) = (
     select 
       a.base_wt  - x.wt,
       a.base_amt - x.amt
     from (
      select 
        b.item, 
        sum(b.wt )  wt, 
        sum(b.amt) amt 
      from 
        b
      where 
        outday between date '2014-01-05' and date '2014-01-07'
      group by
        item
     ) x
     where
       x.item = a.item
  )

另见this sql fiddle。

如何使用Oracle Update Select Statement？

2 个答案: