# 安装mysql
1．查看mysql是否安装，如果安装了，卸载mysql
（1）查看
[root@hadoop102 桌面]# rpm -qa|grep mysql
mysql-libs-5.1.73-7.el6.x86_64
（2）卸载
[root@hadoop102 桌面]# rpm -e --nodeps mysql-libs-5.1.73-7.el6.x86_64
2．下载安装mysql
下载mysql源安装包
[root@hadoop102 software]# wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
安装mysql源
[root@hadoop102 software]# yum localinstall mysql57-community-release-el7-8.noarch.rpm
3、检查mysql源是否安装成功（如果出现下图情况即为安装成功）
[root@hadoop102 software]# yum repolist enabled | grep "mysql.*-community.*"
4、安装mysql
1．安装mysql服务端
[root@hadoop102 software]# yum install mysql-community-server
2．启动mysql
systemctl start mysqld
3．检查mysql的启动状态（如果有running的话就成功了）
systemctl status mysqld
4．启动mysql
[root@hadoop102 mysql-libs]# service mysql start
5、设置开机启动
systemctl enable mysqld
systemctl daemon-reload
6、修改root登陆
grep 'temporary password' /var/log/mysqld.log
7、如果上述未查到的话请执行下面操作
mysql -u root -p
设置密码的时候出现的两次错误
mysql> set password = password('123456a');
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables opt
ion so it cannot execute this statement
mysql> flush privileges;
Query OK, 0 rows affected (0.10 sec)
mysql> set password = password('123456a');
ERROR 1133 (42000): Can't find any matching row in the user table
mysql> set password for 'root'@'localhost'= password('123456a');
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
exit
6、MySql中user表中主机配置
配置只要是root用户+密码，在任何主机上都能登录MySQL数据库。
1．进入mysql
[yrx@hadoop102 mysql-libs]# mysql -uroot -p123456
2．显示数据库
mysql>show databases;
3．使用mysql数据库
mysql>use mysql;
4．展示mysql数据库中的所有表
mysql>show tables;
5．展示user表的结构
mysql>desc user;
6．查询user表
mysql>select User, Host, Password from user;
7．修改user表，把Host表内容修改为%
mysql>update user set host='%' where host='localhost';
8．删除root用户的其他host
mysql>delete from user where Host='hadoop102';
mysql>delete from user where Host='127.0.0.1';
mysql>delete from user where Host='::1';
9．刷新
mysql>flush privileges;
10．退出
mysql>quit;
