比如说一个数据库有id，name，score三列，其中存在name与score均相同的两行或多行。如何清除name与score都相同的重复行呢
先找出相同行的id，sql如下：
微信扫一扫SELECT
DISTINCT(t_s.id)
FROM
`t_score` t_s
INNER JOIN ( SELECT * FROM t_score ) AS ts ON t_s.NAME = ts.NAME
AND t_s.score = ts.score
AND t_s.id != ts.id
order by t_s.id asc;
如果删除的话，在这个基础上，再加一层删除操作：
DELETE
FROM
t_score
WHERE
id IN (
SELECT
a.id
FROM
(
SELECT DISTINCT
( t_s.id ) AS id
FROM
`t_score` t_s
INNER JOIN ( SELECT * FROM t_score ) AS ts ON t_s.NAME = ts.NAME
AND t_s.score = ts.score
AND t_s.id != ts.id
ORDER BY
t_s.id ASC
) a
);
亲测有效，希望可以帮助你！（不要忘了给分哦！）
select DISTINCT from table
select * from tab t
where (t.name,t.score) in (select name,score from tab group by name,score having count(*)> 1 -- 查询重复的数据
and rowid not in (select min(rowid) from tab group by name,score having count(*)>1); -- 加上这个可以保留一个
rowid 是oracle的唯一标识 mysql用_rowid试下
删除就是把查到的删掉就行
查询：
select * from test where id not in( select MAX(id) as id from test group by name, score) //test改为你自己的数据库名
删除：
delete from test where id in (
select test1.id from test as test1, test as test2 where test1.name = test2.name and test1.score = test2.score and test1.id < test2.id)
应该还是挺容易理解的
试试看
--select
select * from your_table where id in (select max(id) from your_table group by name, score having count(id)>1)
--delete
delete from your_table where id in (select max(id) from your_table group by name, score having count(id)>1);