如何在MYSQL中编写'WHEN MATCHED THEN UPDATE‘

Question

在DB2中，我可以编写

 MERGE INTO    Table1 AS A
       USING (
       SELECT *
   FROM        TABLE2
   WHERE        NO.1 = NO.2) AS B ON
   A.TOKEN_ID = B.TOKEN_ID
   WHEN MATCHED THEN UPDATE
   SET        A.LINK_POSTING_IND = 1;

但是MYSQL不支持合并，那么我如何用MYSQL重写这段代码呢？

Answer 1

您可以使用update join在MySQL中重新表述merge语句：

UPDATE Table1 A
INNER JOIN
(
    SELECT TOKEN_ID
    FROM TABLE2
    WHERE NO.1 = NO.2
) B
    ON A.TOKEN_ID = B.TOKEN_ID
SET
    LINK_POSTING_IND = 1;