准备数据 2,b 3,c 4,d 7,y 8,u 2,bb 3,cc 7,yy 9,pp
建表: create table a(id int,name string) row format delimited fields terminated by ‘,‘; create table b(id int,name string) row format delimited fields terminated by ‘,‘;
导入数据: load data local inpath ‘/root/hivedata/a.txt‘ into table a; load data local inpath ‘/root/hivedata/b.txt‘ into table b;
inner join 只打印能匹配上的数据,没有匹配上的不输出
select * from a inner join b on a.id =b.id;
left join 只打印能匹配上的数据,没有匹配上的不输出
select * from a left join b on a.id=b.id;
right join
select * from a right join b on a.id=b.id;
full outer join
select * from a full outer join b on a.id=b.id;
left outer join
left semi join
select * from a left semi join b on a.id=b.id;
相当于
select * from a where a.id exists(select b.id from b); 在hive中效率极低
原文地址:https://www.cnblogs.com/feifeicui/p/10284854.html
时间: 2024-11-08 17:02:16