UPDATE A.A3 = A.A3+B.B3 的問題
表A 結構 : A1 , A2 ,A3
表B 結構: B1, B2, B3
其中 A1 ,B1 為PK ,切值相同 就是可以使用A1 = B1 了.
請問用SQL 陳述式或過程該如何?如下的功能???
更新A 表的 A3 ,用A.A3 與B.B3之和更新.
3>update A
set A3 = (select A.A3 + B.B3 from B where A.A1 = B.B1) ;
7>update (select a1,a3,b1,b3 from a,b where a1=b1) set a3=a3+b3
| 開執行計畫, 談論效率是沒有太多的意義的^_^.. 三樓的寫法與7樓的寫法得到的結果是不同的. 三樓的寫法會更新所有記錄, 而7樓的寫法只修改兩者相交的相關記錄資訊. 7樓的寫法可以更加容易的控制這條update語句的執行計畫, 不過要求B表必須在對應的欄位上有主鍵索引:) , 在B表在對應欄位上有主鍵索引的時候, 建議使用7樓的寫法. 可以參考一下這個文章^_^ http://www.cnoug.org/viewthread.php?tid=44070(測試沒有成功..不知道怎麼搞的.)參考了下面的:非常佩服。抱著學習的態度，重寫了一下三樓的，在沒有主鍵的情況，請指教：
update a
set a3=(select a3+b3 from b where a1=b1)
where a1=(select b1 from b where a1=b1)如下:update con_eme_on20050309 a set a.con_price=(select a.con_price+(b.annuity-a.annuity)+(b.nojob-a.nojob)+(b.medicare-a.medicare)+(b.birthfee-a.birthfee)+(b.bruisefee-a.bruisefee) from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.emp_base=(select b.emp_base from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.annuity=(select b.annuity from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.nojob=(select b.nojob from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.medicare=(select b.medicare from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.birthfee=(select b.birthfee from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.bruisefee=(select b.bruisefee from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.nojobbase=(select b.nojobbase from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.mediabase=(select b.mediabase from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.birthbase=(select b.birthbase from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.bruisebase=(select b.bruisebase from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base)
where a.emp_cod in(select b.emp_cod from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base)公積金:update con_eme_on20050309 a set a.con_price=(select a.con_price+(b.accumulation-a.accumulation) from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.accumulation=(select b.accumulation from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.accumulationbase=(select b.accumulationbase from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base),a.accumulationbase1=(select b.accumulationbase1 from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base)
where a.emp_cod in(select b.emp_cod from con_eme_on200404 b where a.emp_cod=b.emp_cod and a.if_act='1' and a.emp_base!=b.emp_base)
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