Hive安装与操作

目录

环境

数据

实验步骤与结果

（1）环境启动

（2）Hive基本操作

---

环境

Hadoop集群开发环境、mysql、Hive环境

数据

course.txt、sc.txt、student.txt

实验步骤与结果

（1）环境启动

        ①执行命令：“start-all.sh”                               #启动hadoop服务，

        ②执行命令：“service mysql start”                  #启动mysql服务

        ③执行命令：”hive”                                         #启动hive

        执行命令：“mysql -uroot -p”                            #启动mysql，需输入密码进入

        如果正确，结果就如下图

（2）Hive基本操作

        ①表的基本操作

                hive的清屏命令    ctrl+l

                删除表  ：hive> drop table if exists表名;

                看一下数据库

                

                创建数据库 输入：create database studentInfo；

                

                接下来在studentInfo这个数据库中建表

                输入：use studentInfo;

                

                 建表  输入： create table student(Sno int,Sname string,Sex string,Sage int,Sdept string) row format delimited fields terminated by ‘,’ stored as textfile;

                

        ​​​​​​        create table course(Cno int,Sname string) row format delimited fields terminated by ‘,’ stored as textfile;

                

                 create table sc(Sno int,Cno int,Grade int) row format delimited fields terminated by ‘,’ stored as textfile;

                

               （先进库才能show tables）

                

        ②数据加载与录入

                在hadoop家目录下导入表

                

                 

                 接着去hive下输入：load data local inpath ‘/home/hadoop/student.txt’ overwrite into table student;

                

                 同时还有另外两个表 

                输入：load data local inpath ‘/home/hadoop/course.txt’ overwrite into table course;

                输入：load data local inpath ‘/home/hadoop/sc.txt’ overwrite into table sc;

                 

                 ③开始测试（类SQL语句）

                （注意要在自己的那个数据库里   use database）

                查询全体学生的学号和姓名，输入：select Sno,Sname from student;

                

                查询选修课程的学生姓名，输入：select distinct Sname from student inner join sc on student.Sno=Sc.Sno  （select distinct用于返回唯一不同的值。inner join内连接）（每一次这种查找都会通过mapreduce进行操作可以看到 ） 

                

                

                 查询学生的总人数，输入：select count(*) from student