一个关于hive的官网示例

创建表格

CREATE TABLE u_data (
  userid INT,
  movieid INT,
  rating INT,
  unixtime STRING)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY '\t'
STORED AS TEXTFILE;

下载数据

# wget http://files.grouplens.org/datasets/movielens/ml-100k.zip

And load u.data into the table that was just created:

hive> LOAD DATA LOCAL INPATH './ml-100k/u.data'
OVERWRITE INTO TABLE u_data;

Create weekday_mapper.py:

[root@master hive]# cat weekday_mapper.py 
import sys
import datetime

for line in sys.stdin:
  line = line.strip()
  userid, movieid, rating, unixtime = line.split('\t')
  weekday = datetime.datetime.fromtimestamp(float(unixtime)).isoweekday()
  print '\t'.join([userid, movieid, rating, str(weekday)])

创建hive脚本如下
Use the mapper script:

[root@master hive]# cat offical_new_sample.hive 
CREATE TABLE u_data_new (
  userid INT,
  movieid INT,
  rating INT,
  weekday INT)
ROW FORMAT DELIMITED
FIELDS TERMINATED BY '\t';

add FILE weekday_mapper.py;

INSERT OVERWRITE TABLE u_data_new
SELECT
  TRANSFORM (userid, movieid, rating, unixtime)
  USING 'python weekday_mapper.py'
  AS (userid, movieid, rating, weekday)
FROM u_data;

SELECT weekday, COUNT(*)
FROM u_data_new
GROUP BY weekday;

执行脚本

[root@master hive]# hive -f offical_new_sample.hive