Hive基本操作与应用

通过hadoop上的hive完成WordCount

启动hadoop

ssh localhost
cd /usr/local/hadoop
./sbin/start-dfs.sh
cd /usr/local/hive/lib
service mysql start
start-all.sh

Hdfs上创建文件夹

hdfs dfs -mkdir test1
hdfs dfs -ls /user/hadoop

上传文件至hdfs

hdfs dfs -put ./try.txt test1
hdfs dfs -ls /user/hadoop/test1

启动Hive

hive

创建原始文档表

create table docs(line string)

导入文件内容到表docs并查看

1 2	`load data inpath` `'/user/hadoop/tese1/try.txt'` `overwrite` `into` `table docs` `select` `*` `from` `docs`

用HQL进行词频统计，结果放在表word_count里

1	`create table word_count` `as` `select` `word,count(1)` `as` `count` `from` `(select` `explode(split(line," "))` `as` `word` `from` `docs) word` `group` `by` `word order` `by` `word;`

查看统计结果

show tables;
select * from word_count;