1.5 Hive初步使用和安装MySQL

一、HQL初步试用

1、创建一个student表

#创建一个student表
hive> create table student(id int, name string) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t';
OK
Time taken: 0.028 seconds
hive> show tables;
OK
bf_log
student
Time taken: 0.01 seconds, Fetched: 2 row(s)

#因为数据是存在HDFS的文件中，ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' 就是指定数据之间的分隔符；

2、准备测试数据

[root@hadoop-senior datas]# touch student.txt

[root@hadoop-senior datas]# vim student.txt     #制表符分割
1001    zhangsan
1002    lisi
1003    wangwu

3、加载数据到hive表中

hive> load data local inpath '/opt/datas/student.txt' into table student;
Copying data from file:/opt/datas/student.txt
Copying file: file:/opt/datas/student.txt
Loading data to table default.student
Table default.student stats: [numFiles=1, numRows=0, totalSize=45, rawDataSize=0]
OK
Time taken: 0.222 seconds

4、查询

#查询全部，不会走MapReduce
hive> select * from student;
OK
1001    zhangsan
1002    lisi
1003    wangwu
Time taken: 0.023 seconds, Fetched: 3 row(s)

#查询部分，就会走MapReduce
hive> select id from student;
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks is set to 0 since there's no reduce operator
Starting Job = job_1554717689707_0003, Tracking URL = http://hadoop-senior.ibeifeng.com:8088/proxy/application_1554717689707_0003/
Kill Command = /opt/modules/hadoop-2.5.0/bin/hadoop job  -kill job_1554717689707_0003
Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
2019-04-18 18:04:48,120 Stage-1 map = 0%,  reduce = 0%
2019-04-18 18:04:53,240 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.85 sec
MapReduce Total cumulative CPU time: 850 msec
Ended Job = job_1554717689707_0003
MapReduce Jobs Launched:
Job 0: Map: 1   Cumulative CPU: 0.85 sec   HDFS Read: 268 HDFS Write: 15 SUCCESS
Total MapReduce CPU Time Spent: 850 msec
OK
1001
1002
1003
Time taken: 10.565 seconds, Fetched: 3 row(s)

二、安装mysql存储元数据

1、准备安装包

#卸载自带的mysql
[root@hadoop-senior softwares]# rpm -qa |grep mysql
mysql-libs-5.1.71-1.el6.x86_64

[root@hadoop-senior softwares]# rpm -e mysql-libs-5.1.71-1.el6.x86_64 --nodeps

#
[root@hadoop-senior ~]# cd /opt/softwares/

[root@hadoop-senior softwares]# unzip mysql-libs.zip

#
[root@hadoop-senior softwares]# cd mysql-libs

[root@hadoop-senior mysql-libs]# ls
MySQL-client-5.6.24-1.el6.x86_64.rpm  mysql-connector-java-5.1.27.tar.gz  MySQL-server-5.6.24-1.el6.x86_64.rpm

2、安装启动

#安装server端
[root@hadoop-senior mysql-libs]# rpm -ivh MySQL-server-5.6.24-1.el6.x86_64.rpm        #会生成随机密码，在/root/.mysql_secret里

[root@hadoop-senior ~]# cat /root/.mysql_secret
# The random password set for the root user at Fri Apr 19 09:29:24 2019 (local time): O9zwV6WQljcMkzRa

#安装client
[root@hadoop-senior mysql-libs]# rpm -ivh MySQL-client-5.6.24-1.el6.x86_64.rpm

#启动
[root@hadoop-senior mysql-libs]# service mysql start
Starting MySQL.                                            [确定]

[root@hadoop-senior mysql-libs]# service mysql status
MySQL running (24085)                                      [确定]

[root@hadoop-senior mysql-libs]# netstat -ntlp |grep 3306
tcp        0      0 :::3306                     :::*                        LISTEN      24085/mysqld

3、连接mysql，改密码

#改密码
[root@hadoop-senior mysql-libs]# mysql -uroot -pO9zwV6WQljcMkzRa        #密码是刚才自动生成的
......
mysql> set password=password('123456');
Query OK, 0 rows affected (0.00 sec)
mysql> exit
Bye

#新密码连接
[root@hadoop-senior mysql-libs]# mysql -uroot -p123456
......
mysql>

4、授权mysql的root用户

#
[root@hadoop-senior ~]# hostname
hadoop-senior.ibeifeng.com

#连入mysql操作
mysql> grant all privileges on *.* to root@'%' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> grant all privileges on *.* to 'root'@'hadoop-senior.ibeifeng.com' identified by '123456' with grant option;
Query OK, 0 rows affected (0.00 sec)

mysql> select User,Host,Password from user;
+------+----------------------------+-------------------------------------------+
| User | Host                       | Password                                  |
+------+----------------------------+-------------------------------------------+
| root | localhost                  | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| root | hadoop-senior.ibeifeng.com | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| root | 127.0.0.1                  | *D25D1C957F2E56F330D565256AE9D88C49E7194D |
| root | ::1                        | *D25D1C957F2E56F330D565256AE9D88C49E7194D |
| root | %                          | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+------+----------------------------+-------------------------------------------+
5 rows in set (0.00 sec)

mysql> delete from user where User='root' and Host='hadoop-senior.ibeifeng.com';
Query OK, 1 row affected (0.00 sec)

mysql> delete from user where User='root' and Host='127.0.0.1';
Query OK, 1 row affected (0.00 sec)

mysql> delete from user where User='root' and Host='::1';
Query OK, 1 row affected (0.00 sec)

mysql> delete from user where User='root' and Host='localhost';
Query OK, 1 row affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> select User,Host,Password from user;
+------+------+-------------------------------------------+
| User | Host | Password                                  |
+------+------+-------------------------------------------+
| root | %    | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+------+------+-------------------------------------------+
1 row in set (0.00 sec)

mysql> exit;