一般我们选择安装Centos的最小安装，然后我们在使用好多工具的时候就会报错！wget不会默认被安装。需要安装的看我之前的博客。
1、配置YUM源
下载mysql源安装包
[root@localhost~]#wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm安装mysql源
[root@localhost~]# yum localinstall mysql57-community-release-el7-8.noarch.rpm
提示【Is this ok [y/d/N]: y 输入y回车】
检查MySQL源是否安装成功
[root@localhost ~]# yum repolist enabled | grep “mysql.-community.”2、安装MySQL
[root@localhost ~]# yum install mysql-community-server注意：安装过程中提示【Is this ok [y/d/N]: y 输入y回车】
出现以下表示安装成功：
Replaced:
mariadb-libs.x86_64 1:5.5.56-2.el7 Complete! 3、启动MySQL服务
[root@localhost ~]# systemctl start mysqld
查看MySQL的启动状态
[root@localhost ~]# systemctl status mysqld4.开机启动
[root@localhost ~]# systemctl enable mysqld
[root@localhost ~]# systemctl daemon-reload查看mysql下root账号的默认密码
mysql5.7安装完成之后，在/var/log/mysqld.log文件中给root生成了一个默认密码。通过下面的方式找到root默认密码，然后登录mysql。
命令：grep ‘temporary password’ /var/log/mysqld.log
[root@localhost /]# grep 'temporary password' /var/log/mysqld.log
2017-10-17T08:07:03.797098Z 1 [Note] A temporary password is generated for root@localhost: 3prjY9ktM,eL [root@localhost /]# 默认的密码是：3prjY9ktM,eL修改配置文件
默认配置文件路径
配置文件：/etc/my.cnf
日志文件：/var/log//var/log/mysqld.log
服务启动脚本：/usr/lib/systemd/system/mysqld.service
socket文件：/var/run/mysqld/mysqld.pid
修改my.cnf文件
修改密码策略
mysql的密码策略分为三种：
0或LOW：Length
1或MEDIUM：Length; numeric, lowercase/uppercase, and special characters
2或STRONG：Length; numeric, lowercase/uppercase, and special characters; dictionary file
在my.cnf文件中增加如下设置
如果不需要密码策略，禁用密码策略
validate_password = off
密码选择策略 0-LOW，1-MEDIUM，2-STRONG需要提供密码字典文件
validate_password_policy = 0
修改字符编码为utf8
在[mysqld]下增加如下配置
character_set_server = utf8
init_connect = ‘SET NAMES utf8’
例：
[root@localhost /]# cd /etc/
[root@localhost etc]# vi my.cnf
validate_password = off# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M # # Remove leading # to turn on a very important data integrity option: logging # changes to the binary log between backups. # log_bin # # Remove leading # to set options mainly useful for reporting servers. # The server defaults are faster for transactions and fast SELECTs. # Adjust sizes as needed, experiment to find the optimal values. # join_buffer_size = 128M # sort_buffer_size = 2M # read_rnd_buffer_size = 2M datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid validate_password = off #设置禁用密码策略 character_set_server = utf8 #修改字符编码为utf8 init_connect = 'SET NAMES utf8'保存my.cnf并重启mysql服务是配置生效
命令：systemctl restart mysqld
登录mysql
命令：mysql -uroot -p
输入密码：默认为刚才查到的密码”3prjY9ktM,eL”
[root@localhost etc]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.20 Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> alter user 'root'@'localhost' identified by '123'; #修改密码
mysql> grant all privileges on *.* to 'root' @'%' identified by 'yourpassword'; #允许访问mysql
mysql> flush privileges; #使生效