如果MySQL中存在重复行

Question

在MSSQL中它正在工作;

IF EXISTS (SELECT id FROM T1 WHERE id=X) 
    BEGIN INSERT INTO T1(C1, C2, C3) 
     (SELECT C1, C2, 'Different Value' AS C3 FROM T1 WHERE id=X) 
    END 

什么是MYSQL的对应语法。

预先感谢您

Answer 1

刚：

INSERT INTO T1(C1, C2, C3) 
SELECT C1, C2, 'Different Value' AS C3 
FROM T1 
WHERE id=X 

如果记录id = X存在，它会被插入，否则不是。