hdfs数据

从本地源中加载数据到hive表中
load data inpath '/ict01/department.txt' into table department.txt;

创建外部表employee
create external table employee(id int,name string ,subject string,score  float)  row format delimited fields terminated by ',' stored as textfile ;

create table employee(
user_id int,
username string,
dept_id int)
row format delimited fields terminated by ','  
stored as textfile ;

select * from department  limit 5;

可以对两张以上的表进行连接操作，下面的SQL语句查询员工的名字、部门名字及其的薪水：
执行语句：
select e.username,d.dept_name,s.salarys 
from cx_table_employee e 
join cx_table_department d 
on e.dept_id = d.dept_id 
join cx_table_salary s 
on e.user_id = s.userid;