CentOS 7 安装 MySQL 5.7

查看yum是否安装过mysql

yum list installed mysql*

卸载
yum remove mysql 按2下tab 键能提示需要卸载的包，复制就可以了

yum remove mysql-community-client mysql-community-common mysql-community-libs mysql-community-libs-compat mysql-community-server mysql57-community-release
rm -rf /var/lib/mysql  
rm /etc/my.cnf

下载

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

安装

rpm -ivh mysql57-community-release-el7-8.noarch.rpm

安装 MySQL

yum install mysql-server

启动前修改数据存放路径
vim /etc/my.cnf
datadir=/var/lib/mysql 改为 datadir=/data/mysql

需要给mysql 默认用户mysql 赋予权限 ，不然启动会报错

chown mysql:mysql -R /data/mysql

启动，产看初始密码

service mysqld start
grep "password" /var/log/mysqld.log

返回： 最后就是密码
A temporary password is generated for root@localhost: hilX0U!9i3_6

登录

mysql -u root -philX0U!9i3_6

登录后需先修改密码，默认情况下密码是不能修改为123456的，如果需要修改成简单密码先修改mysql 规则

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

修改密码

SET PASSWORD = PASSWORD('123456');
ALTER USER 'root'@'localhost' PASSWORD EXPIRE NEVER;
flush privileges;

root 任意ip 访问

grant all privileges on *.* to root@"%" identified by "new password";
flush privileges;

MySQL控制命令：启动、停止、重启、查看状态

service mysqld start
service mysqld stop
service mysqld restart
service mysqld status

systemctl start mysqld
service mysqld stop
service mysqld restart
systemctl status mysqld