hive基本操作与应用

通过hadoop上的hive完成WordCount

启动hadoop

start-all.sh

Hdfs上创建文件夹

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

上传文件至hdfs

hdfs dfs -put ./test.txt input
hdfs dfs -ls /user/hadoop/input

启动Hive

hive

创建原始文档表

create table documents(line string);

导入文件内容到表docs并查看

load data inpath '/user/hadoop/input/test.txt' overwrite into table documents;
select * from documents;

用HQL进行词频统计，结果放在表word_count里

create table word_count as select word,count(1) as count from (se
lect explode(split(line,' ')) as word from

documents

) word group by word order by word;

查看统计结果

show tables;
select * from word_count;