数据库去除重复数据（id除外）

 

第一步：

   (SELECT MIN(s_id) AS s_id FROM student GROUP BY s_name,s_birth,s_sex)//选择出，name,birth,sex不相同的 

   换言之就是不重复的。

第二步:

  (SELECT student.s_id FROM (SELECT MIN(s_id) AS s_id FROM student GROUP BY s_name,s_birth,s_sex) student );

  统计出不重复数据的id；

第三步：

DELETE FROM student 
WHERE s_id NOT IN 
(SELECT student.s_id FROM 
   (SELECT MIN(s_id) AS s_id FROM student GROUP BY s_name,s_birth,s_sex)
 student );

把非这些数据的全部删除