下载mysql-5.7.24的mysql的repo源，此yum源自动下载最新版本。
    下载完成后执行安装

    1. wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm
    2. rpm -ivh mysql57-community-release-el7-8.noarch.rpm
    3. yum -y install mysql-server

    安装完成后
    修改my.cnf文件

    1. vim /etc/my.cnf
    3. [mysqld]
    4. #
    5. # Remove leading # and set to the amount of RAM for the most important data
    6. # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
    7. # innodb_buffer_pool_size = 128M
    8. #
    9. # Remove leading # to turn on a very important data integrity option: logging
    10. # changes to the binary log between backups.
    11. # log_bin
    12. #
    13. # Remove leading # to set options mainly useful for reporting servers.
    14. # The server defaults are faster for transactions and fast SELECTs.
    15. # Adjust sizes as needed, experiment to find the optimal values.
    16. # join_buffer_size = 128M
    17. # sort_buffer_size = 2M
    18. # read_rnd_buffer_size = 2M
    19. datadir=/var/lib/mysql
    20. socket=/var/lib/mysql/mysql.sock
    22. # Disabling symbolic-links is recommended to prevent assorted security risks
    23. symbolic-links=0
    25. log-error=/var/log/mysqld.log
    26. pid-file=/var/run/mysqld/mysqld.pid
    28. # 设置密码安全策略为0,低等级
    29. validate_password_policy=0
    30. # 设置编码
    31. character_set_server=utf8
    32. init_connect='SET NAMES utf8'
    33. # 忽略表名大小写
    34. lower_case_table_names=1
    36. skip-name-resolve

    [可选项 start]
    执行mysqld --initialize 初始化
    如果遇到 unknown variable 'validate_password_policy=0' 错误，在my.cnf中将这个变量注释掉
    如果遇到 The innodb_system data file 'ibdata1' must be writable 错误，执行此命令给mysql data文件夹赋予读写权限 chmod -R 777 /var/lib/mysql
    [可选项 end]

    使用 systemctl start mysqld 启动mysql服务
    使用 grep 'password' /var/log/mysqld.log 获取mysql初始密码
    使用刚刚获取的初始密码登录 mysql -uroot -p
    更改新密码 set password for root@localhost = password('your password');
    创建新用户，授权，刷新权限

    1. grant privileges ON databasename.tablename to 'username'@'host' idendified by 'password';
    2. flush privileges;

    PS.设置mysql自启动

    1. systemctl enable mysqld
    2. systemctl enable daemon-reload