hive基本操作与应用
1.启动hadoop
start-all.sh
2.Hdfs上创建文件夹
hdfs dfs -mkdir testinput
hdfs dfs -ls /user/hadoop
3.上传文件至hdfs
hdfs dfs -put ./test.txt testinput
hdfs dfs -ls /user/hadoop/testinput
4.启动Hive
hive
5.创建原始文档表
create table docs(line string);<br>show tables;
6.导入文件内容到表docs并查看
load data inpath '/user/hadoop/testinput/test.txt' overwrite into table docs;
7.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) from (select explode(split(line,' ')) as word from docs) word group by word;
8.查看统计结果
select * from word_count;