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。