建表操作

1)创建临时库
CREATE DATABASE IF NOT EXISTS youtube;
USE youtube;
	
2)创建表
DROP TABLE IF EXISTS `userid`;
CREATE EXTERNAL TABLE IF NOT EXISTS `userid` (
  id STRING
)
ROW FORMAT DELIMITED 
FIELDS TERMINATED BY '\t'
LINES TERMINATED BY '\n' 
LOCATION '/user/hive/warehouse/youtube.db/data/userid.txt';


DROP TABLE IF EXISTS `users`;
CREATE EXTERNAL TABLE IF NOT EXISTS `users` (
  id STRING,
  uploads INT,
  watches INT,
  friends INT
)
ROW FORMAT DELIMITED 
FIELDS TERMINATED BY '\t'
LINES TERMINATED BY '\n' 
LOCATION '/user/hive/warehouse/youtube.db/data/user.txt';

3)数据加载
insert into table userid select id from users;

4)创建表
DROP TABLE IF EXISTS `users2`;
CREATE EXTERNAL TABLE IF NOT EXISTS `users2` (
  id STRING,
  uploads INT,
  watches INT,
  friends INT
)
ROW FORMAT DELIMITED 
FIELDS TERMINATED BY '\t'
LINES TERMINATED BY '\n' 
LOCATION '/user/hive/warehouse/youtube.db/data/user2.txt';

5)再次数据加载
insert into table userid select id from users2;