如何更新與同一表的另一記錄匹配的表字段

Question

如何更新與同一表的另一記錄匹配的表字段。

UPDATE XXXRLES 
    SET BIZCAT05 = 'S' 
    WHERE (SELECT A.* FROM XXXRLES A, XXXRLES B 
        WHERE 
         A.BIZFLD = B.BIZFLD 
         AND A.BIZOBJ = B.BIZOBJ 
         AND A.BIZRUL = B.BIZRUL 
     ); 

我需要在表XXXRLES的「S」更新域BIZCAT05當且僅當2個記錄有以下3個字段值相同：

BIZFLD 
BIZOBJ 
BIZRUL 

---

如何使這個查詢？

Answer 1

我已經假設你的RDBMS是Oracle，在你提到ROWID之後發表評論。

UPDATE A SET 
    BIZCAT05 = 'S' 
FROM XXXRLES A 
JOIN XXXRLES B ON 
    A.BIZFLD = B.BIZFLD 
    AND A.BIZOBJ = B.BIZOBJ 
    AND A.BIZRUL = B.BIZRUL 
    AND A.ROWID <> B.ROWID 

或使用exists（看起來更清晰，最後對我來說）：

評論後

UPDATE A SET 
    BIZCAT05 = 'S' 
FROM XXXRLES A 
WHERE EXISTS (SELECT 1 
    FROM XXXRLES B 
    WHERE A.BIZFLD = B.BIZFLD 
    AND A.BIZOBJ = B.BIZOBJ 
    AND A.BIZRUL = B.BIZRUL 
    AND A.ROWID <> B.ROWID 
) 

新增：

我不熟悉DB2，但你可以請嘗試：

UPDATE XXXRLES A SET 
    BIZCAT05 = 'S' 
WHERE EXISTS (SELECT 1 
    FROM XXXRLES B 
    WHERE A.BIZFLD = B.BIZFLD 
    AND A.BIZOBJ = B.BIZOBJ 
    AND A.BIZRUL = B.BIZRUL 
    AND A.ROWID <> B.ROWID 
) 

Answer 2

不知道，是正確理解你，試試這個

UPDATE XXXRLES SET BIZCAT05 = 'S' WHERE XXXRLES.ID in 
(SELECT A.ID FROM XXXRLES A,  XXXRLES B 
    WHERE A.BIZFLD = B.BIZFLD AND A.BIZOBJ = B.BIZOBJ AND A.BIZRUL = B.BIZRUL); 

Answer 3

您可以使用RID（）行標識符的內置功能來識別唯一行。 更新查詢可以如下寫：

UPDATE XXXRLES A 
SET BIZCAT05 = 'S' 
WHERE EXISTS (SELECT 1 
       FROM XXXRLES B 
       WHERE A.BIZFLD = B.BIZFLD 
       AND A.BIZOBJ = B.BIZOBJ 
       AND A.BIZRUL = B.BIZRUL 
       AND RID(A) <> RID(B) 
      ) 

請找到該IBM DB2信息中心RID（）函數的詳細信息。 http://publib.boulder.ibm.com/infocenter/dzichelp/v2r2/index.jsp?topic=%2Fcom.ibm.db2z10.doc.sqlref%2Fsrc%2Ftpc%2Fdb2z_bif_rid.htm