mysql表中删除重复记录方法

最高效的删除重复记录方法 (使用ROWID)

例子：

CREATE TABLE EMP(ID NUMBER(10),NAME VARCHAR2(233))
INSERT INTO EMP(ID,NAME) VALUES(1,'张三');
INSERT INTO EMP(ID,NAME) VALUES(2,'张三');
INSERT INTO EMP(ID,NAME) VALUES(1,'张三');

SELECT * FROM EMP; 

DELETE FROM EMP E WHERE E.ROWID>(SELECT MIN(X.ROWID) FROM EMP X WHERE  X.ID = E.ID AND X.NAME=E.NAME);

commit;