如果存在，则在MySQL中重复行

Question

在MSSQL中它正在运行;

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

MYSQL的对应语法是什么。

提前谢谢

Answer 1

只需：

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，则将插入，否则不插入。