如何更新与同一表的另一记录匹配的表字段

Question

如何更新与同一表的另一记录匹配的表字段。

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当且仅当2个记录有以下3个字段值相同：

BIZFLD 
BIZOBJ 
BIZRUL 

---

如何使这个查询？

Answer 1

我已经假设你的RDBMS是Oracle，在你提到ROWID之后发表评论。

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（看起来更清晰，最后对我来说）：

评论后

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，但你可以请尝试：

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，是正确理解你，试试这个

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（）行标识符的内置功能来识别唯一行。 更新查询可以如下写：

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) 
      ) 

请找到该IBM DB2信息中心RID（）函数的详细信息。 http://publib.boulder.ibm.com/infocenter/dzichelp/v2r2/index.jsp?topic=%2Fcom.ibm.db2z10.doc.sqlref%2Fsrc%2Ftpc%2Fdb2z_bif_rid.htm