Linux(CENTOS7) YUM方式安装mysql5.7

　　参考地址:https://www.cnblogs.com/linjiqin/p/7611204.html

　　注:该地址标题写的是CENTOS6.*版本的，但是我在我的CENTOS7.*上面安装是完美进行的

　　下面的内容是我从上面这个地址复制过来的,稍作修改。

下载mysql源安装包
# wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
 
安装mysql源包
# yum localinstall mysql57-community-release-el7-8.noarch.rpm

检查mysql源是否安装成功
# yum repolist enabled | grep "mysql.*-community.*"

看到下图(三个)表示成功：
mysql-connectors-community      MySQL Connectors Community      36
mysql-tools-community           MySQL Tools Community           47
mysql57-community               MySQL5.7 Community Server      189
 
安装MySQL服务
# yum install mysql-community-server

启动MySQL服务
# systemctl start mysqld
 
查看MySQL的启动状态
# systemctl status mysqld

设置开机启动
# systemctl enable mysqld
# systemctl daemon-reload #重新载入
 
查看root默认密码
# grep 'temporary password' /var/log/mysqld.log

修改root密码
# mysql -uroot -p

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'Abc1234!';
或者
mysql> set password for'root'@'localhost'=password('Abc1234!');

注意：mysql5.7默认安装了密码安全检查插件（validate_password），默认密码检查策略要求密码必须包含：大小写字母、数字和特殊符号，并且长度不能少于8位。否则会提示ERROR 1819 (HY000): Your passworddoes not satisfy the current policy requirements错误

添加远程连接登录用户，如：用户名：root，密码：Abc1234!
mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'IDENTIFIED BY 'Abc1234!' WITH GRANT OPTION;

重启mysql服务
# systemctl restart mysqld

我这里使用SQLyog链接的，如果链接报类似下面错误：
    Host ‘’ is not allowed to connect to this MySQL server
请参考下面链接：https://blog.csdn.net/liguoqingxjxcc/article/details/82350411