处理表中重复出现数据,只查询出一条语句

创建一个表

create table peo
(
       name varchar(20),
       age int,
       sex varchar(8)
);

select * from peo;

向表中添加一些有重复的数据:

insert into peo(name,age,sex) values('zhagnsan',21,'F');
insert into peo(name,age,sex) values('zhagnsan',21,'F');
insert into peo(name,age,sex) values('zhagnsan',21,'F');
insert into peo(name,age,sex) values('zhagnsan',21,'F');
insert into peo(name,age,sex) values('zhagnsan',11,'F');
insert into peo(name,age,sex) values('zhagnsan',31,'m');
insert into peo(name,age,sex) values('zhagnsan',23,'F');
insert into peo(name,age,sex) values('lisi',23,'F');
insert into peo(name,age,sex) values('lisi',13,'F');
insert into peo(name,age,sex) values('wangwu',23,'F');
insert into peo(name,age,sex) values('zhaoliu',23,'F');

选出一些数据,这些数据是,所有有名字的都会出现,只是一些重复名字的只会选出一条显示
select s.* from 
(select t.*,row_number() over(partition by name order by name)as group_idx from peo t)s
where s.group_idx=1;

       补充一下row_number的用法:row_number() over(partition by column1 order by column2) group_id:这句话的意思就是,这个表根据column1分组,然后根据column2排序,最后排序出来的序号字段叫group_id。 

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转载自blog.csdn.net/JessieZao/article/details/81359905