【mysql去重】

重复数据查询：

SELECT data1,data2,COUNT(*) FROM table GROUP BY data1,data2 HAVING COUNT(*)>1

删除重复数据（保留id最小的）：

DELETE FROM table
WHERE id NOT IN (
	SELECT * FROM (
    	SELECT MIN(id)
    	FROM radcheck
    	GROUP BY data1,data2
	) AS temp
);