Question

sql语句删除重复内容，保留一条，id不同，通过后面4个字段内容相同则删除该记录

id name class type ct
1 44 55 2 66
2 44 55 2 66
3 11 22 1 33
4 11 22 1 33
执行sql语句后，变为
id name class type ct
2 44 55 2 66
4 11 22 1 33

Answer 1

可亏裂仿以这样销纤删除源毕
delete from table1 where id not in(
select id from table1 a where id = (select max(id) from table1 b where a.name = b.name and a.class = b.class and a.type = b.type and a.ct = b.ct))

Answer 2

刚经过测试的，版本在MSSQL05以昌蠢上就成。提供质量保证。
delete from t1
where id in (select id from
(select id,row_number() over(partition by name,class,[type],ct order by id desc, name,class,[type],ct)as num from t1)as tmp where num>1)

呵呵，耐盯陪祝你好则核运~

Answer 3

delete from 表名 where id not in(select max(id) from 表名 group by [name],class,[type],ct)
根据后面4个字段分组漏败查梁帆询不是重复的id,
删除重复的橡搜雹ID

追问

表中id没有重复的，就是id不同，后面4个字段内容相同的时候，把这些id不同，后面字段内容相同的数据删除后保留一条