mysql 安装

一、卸载现有的

rpm -qa | grep mysql

rpm -e  普通删除
rpm -e --nodeps  强力删除，消除依赖

检测是否存在mariadb
rpm -qa | grep mariadb

二、下载解压

wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.25-linux-glibc2.12-x86_64.tar.gz

目录准备：
/usr/local/mysql/mysql57/data

三、用户组，目录赋予用户组

[root@iz2ze0ebr6tsvnum4obdcpz mysql57]# cat /etc/group | grep mysql
mysql:x:27:
[root@iz2ze0ebr6tsvnum4obdcpz mysql57]# cat /etc/passwd | grep mysql
mysql:x:27:27:MariaDB Server:/var/lib/mysql:/sbin/nologin

没有则创建
chown -R mysql.mysql /opt/mysql/mysql-5.7.25

四、创建/etc/cof 文件

[mysqld]
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES 
 
basedir = /usr/local/mysql/mysql57
datadir = /usr/local/mysql/mysql57/data
port = 3306
socket = /tmp/mysql.sock
character-set-server=utf8
 
log-error = /usr/local/mysql/mysql57/data/mysqld.log
pid-file = /usr/local/mysql/mysql57/data/mysqld.pid

五、初始化

cd /usr/local/mysql/mysql57/
./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql/mysql57/ --datadir=/usr/local/mysql/mysql57/data/

//会显示初始密码  eHW1<#>o.Ltx

初始化完成之后，查看日志
/usr/local/mysql/mysql57/data/mysqld.log

把启动脚本开机初始化目录中
cp support-files/mysql.server /etc/init.d/mysql

注意点：
如果失败的话，把data目录下文件清空，再执行mysqld --initialize

六、启动服务

service mysql start

cd /opt/mysql/mysql-5.7.25
./bin/mysql -u root -p

修改密码：

mysql> set password=password('123456');
mysql> grant all privileges on *.* to root@'%' identified by '123456';
mysql> flush privileges;

添加远程访问权限

mysql> use mysql;
mysql> update user set host='%' where user = 'root';
mysql> flush privileges;

重启生效

service mysql restart