Centos7 yum安装Mysql

1.下载mysql的repo源

$ wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm

2.安装mysql-community-release-el7-5.noarch.rpm包

$ sudo rpm -ivh mysql-community-release-el7-5.noarch.rpm

安装这个包后，会获得两个mysql的yum repo源：/etc/yum.repos.d/mysql-community.repo，/etc/yum.repos.d/mysql-community-source.repo。

3.安装mysql

$ sudo yum install mysql-server

根据提示安装就可以了,不过安装完成后没有密码,需要重置密码

4.重置mysql密码

$ mysql -u root

登录时有可能报这样的错：ERROR 2002 (HY000): Can‘t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock‘ (2)，原因是/var/lib/mysql的访问权限问题。下面的命令把/var/lib/mysql的拥有者改为当前用户：

$ sudo chown -R root:root /var/lib/mysql

重启mysql服务

$ service mysqld restart

接下来登录重置密码：

$ mysql -u root //直接回车进入mysql控制台
mysql > use mysql;
mysql > update user set password=password(‘123456’) where user=’root’;
mysql > exit;

然后测试登录有可能报错
mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: YES)
原因是在user表中有用户名为空的账户，登录的时候会首先验证这些空的用户名的密码。

执行如下命令解决：
$ mysql -u root
mysql > use mysql
mysql > update user set password_expired = “Y” where user=”root”;
mysql > flush privileges;
mysql> quit

$ mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 5.6.40

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

完成。