一、筹备环境

1、查看以后环境是否装置MySQL，如果有则删除卸载

rpm -qa | grep mysqlpm -qa |grep mariadbyum remove mariadb-libs-5.5.64-1.el7.x86_64

2、查看my.cnf文件，如果有则删除

rm /etc/my.cnfrm /etc/mysql/my.cnf

二、下载安装MySQL

1、从官网下载MySQL5.7.34

1. 官网地址：https://downloads.mysql.com/archives/community2. MySQL5.7.34 安装包下载地址：https://downloads.mysql.com/archives/get/p/23/file/mysql-5.7.34-linux-glibc2.12-x86_64.tar.gz

2、装置MySQL 5.7.34

1.创立mysql用户groupadd mysqluseradd -r -g mysql -s /bin/false mysql2.解压安装包cd /usr/localtar zxvf mysql-5.7.34-linux-glibc2.12-x86_64.tar.gz -C /usr/localln -s mysql-5.7.34-linux-glibc2.12-x86_64 mysqlcd mysql3.创立run、logs门路mkdir run && chown mysql.mysql runmkdir logs && chown mysql.mysql logs4.初始化mysqlbin/mysqld --initialize --user=mysql5.首次启动mysql，记录此命令返回的随机明码bin/mysqld_safe --user=mysql &[Note] A temporary password is generated for root@localhost: :qq:&XSwq6HL6.创立启动脚本cp support-files/mysql.server /etc/init.d/mysql.server/etc/init.d/mysqld status  /etc/init.d/mysqld start/etc/init.d/mysqld stop/etc/init.d/mysqld restart7.设置mysql环境变量echo 'export PATH=$PATH:/usr/local/mysql/bin' >> /etc/profile

3、批改MySQL明码，创立用户

mysql -u root -p':qq:&XSwq6HL'ALTER USER 'root'@'localhost' IDENTIFIED BY 'root-password';CREATE USER 'root'@'127.0.0.1' IDENTIFIED BY 'root-password';CREATE USER 'root'@'::1' IDENTIFIED BY 'root-password';

4、创立mysql配置文件

1.my.cnf 文件优先级/etc/my.cnf  #Global options/etc/mysql/my.cnf  #Global optionsSYSCONFDIR/my.cnf  #Global options$MYSQL_HOME/my.cnf  #Server-specific options (server only)2./etc/mysql/my.cnf[client]user = rootpassword = 123456port = 3306socket = /usr/local/mysql/run/mysql.sock[mysqld]port = 3306socket = /usr/local/mysql/run/mysql.sockpid_file = /usr/local/mysql/run/mysql.piddatadir = /usr/local/mysql/datacharacter-set-server = utf8mb4

5、重启mysql失效/etc/mysql/my.cnf

/etc/init.d/mysqld restart