centOS7安装mysql

1.删除CentOS默认安装的mariadb数据库

yum remove mariadb-libs.x86_64

2.下载mysql源文件 cd /tmp 目录下

wget https://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm

3.安装源

yum localinstall mysql57-community-release-el7-8.noarch.rpm

4.安装MySQL

yum install mysql-community-server

5.启动

sudo service mysqld start

6.查看默认密码

cat /var/log/mysqld.log | grep "password"

7.重置密码，查看文章(需先用默认密码登录mysql )
http://blog.sina.com.cn/s/blog_a0d71a9d0102wlz3.html

mysql -u root -p

注意：如果只想设置简单密码需要修改两个全局参数：

mysql> set global validate_password_policy=0;
mysql> set global validate_password_length=1;

mysql> SET PASSWORD = PASSWORD('123456');   //123456 是重置的新密码

8.设置root可以远程连接

update  mysql.`user` set Host = '%' where User = 'root' and Host = 'localhost';

flush privileges; // 或者重启服务 sudo service mysqld restart

9.关闭防火墙

sudo service firewalld stop