Hive 操作与应用 词频统计

一、hive用本地文件进行词频统计

1.准备本地txt文件

mkdir wc
cd wc
 echo "hadoop hbase" > f1.txt
 echo "hadoop hive" > f2.txt

 

 

 

2.启动hadoop，启动hive

start-all.sh
jps
hive

 

 

 

3.创建数据库，创建文本表

use hive;
create table if not exists wctext(line string);
show tables;

 

 

 

4.映射本地文件的数据到文本表中

load data local inpath '/home/hadoop/wc/f1.txt' into table wctext;
load data local inpath '/home/hadoop/wc/f2.txt' into table wctext;
select * from wctext;

 

5.hql语句进行词频统计交将结果保存到结果表中。

SELECT word, count(1) AS count FROM (SELECT explode(split(line, ' ')) AS

 word FROM wctext) w GROUP BY word ORDER BY word;
CREATE table wc as SELECT word, count(1) AS count FROM (SELECT explode(split(line, ' ')) AS word FROM wctext) w GROUP BY word ORDER BY word;

 

 

 

 

6.查看统计结果

select * from wc;

 

 

二、hive用HDFS上的文件进行词频统计

1.准备电子书或其它大的文本文件

wget -O f3.txt http://www.gutenberg.org/files/2701/2701-0.txt

 

 

2.将文本文件上传到HDFS上

hdfs dfs -put ~/wc/f3.txt input

 

 

 

3.创建文本表

create table if not exists docs(line string);
show tables;

 

 

 

4.映射HDFS中的文件数据到文本表中

load data inpath '/user/hadoop/input/f3.txt' into table docs;

 

 

 

5.hql语句进行词频统计交将结果保存到结果表中

CREATE table wctest as SELECT word, count(1) AS count FROM (SELECT explode(split(line, ' ')) AS word FROM docs) w GROUP BY word ORDER BY word;
SELECT word, count(1) AS count FROM (SELECT explode(split(line, ' ')) AS word FROM docs) w GROUP BY word ORDER BY word;

 

6.查看统计结果