mysql的rpm包下载地址

https://dev.mysql.com/downloads/mysql/5.7.html#downloads

下载，mysql-5.7.29-1.el7.x86_64.rpm-bundle.tar 大小520.5M

卸载CentOS7.4系统自带的mariadb

[root@localhost ~]# rpm -qa|grep mariadb
mariadb-libs-5.5.56-2.el7.x86_64
[root@localhost ~]# rpm -qa|grep mysql
[root@localhost ~]# rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64
[root@localhost ~]# rpm -qa|grep mariadb
[root@localhost ~]# 

将mysql-5.7.29-1.el7.x86_64.rpm-bundle.tar 拷贝到/tmp下，并解压

[root@localhost tmp]# tar xvf mysql-5.7.29-1.el7.x86_64.rpm-bundle.tar 
mysql-community-embedded-devel-5.7.29-1.el7.x86_64.rpm
mysql-community-test-5.7.29-1.el7.x86_64.rpm
mysql-community-embedded-5.7.29-1.el7.x86_64.rpm
mysql-community-embedded-compat-5.7.29-1.el7.x86_64.rpm
mysql-community-libs-5.7.29-1.el7.x86_64.rpm
mysql-community-client-5.7.29-1.el7.x86_64.rpm
mysql-community-server-5.7.29-1.el7.x86_64.rpm
mysql-community-devel-5.7.29-1.el7.x86_64.rpm
mysql-community-libs-compat-5.7.29-1.el7.x86_64.rpm
mysql-community-common-5.7.29-1.el7.x86_64.rpm

依次安装：

mysql-community-common-5.7.29-1.el7.x86_64.rpm、
mysql-community-libs-5.7.29-1.el7.x86_64.rpm、
mysql-community-client-5.7.29-1.el7.x86_64.rpm、
mysql-community-server-5.7.29-1.el7.x86_64.rpm

[root@localhost tmp]# rpm -ivh mysql-community-common-5.7.29-1.el7.x86_64.rpm 
[root@localhost tmp]# rpm -ivh mysql-community-libs-5.7.29-1.el7.x86_64.rpm 
[root@localhost tmp]# rpm -ivh mysql-community-client-5.7.29-1.el7.x86_64.rpm 
[root@localhost tmp]# rpm -ivh mysql-community-server-5.7.29-1.el7.x86_64.rpm 

重启系统，来启动mysql服务

[root@localhost tmp]# reboot

查看防火墙端口，开放3306端口

查看防火墙的状态的命令为：sudo systemctl status firewalld。

打开防火墙的方式有两种，一种是打开后重启会恢复回原来的状态，命令为：sudo systemctl start firewalld；
另一种是打开后重启不会恢复到原来的状态，命令为：sudo systemctl enable firewalld，这种方式输入命令后要重启系统才会生效。

关闭防火墙的方式也有两种，和打开相对应，命令分别为
sudo systemctl stop firewalld
sudo systemctl disable firewalld。

[root@localhost ~]# firewall-cmd --query-port=3306/tcp
no
[root@localhost ~]# firewall-cmd --zone=public --add-port=3306/tcp --permanent
success
[root@localhost ~]# firewall-cmd --reload
success
[root@localhost ~]# firewall-cmd --query-port=3306/tcp
yes
[root@localhost ~]#

获取mysql的root用户的初始密码

[root@localhost ~]# grep 'password' /var/log/mysqld.log 
2020-01-14T01:09:01.515663Z 1 [Note] A temporary password is generated for root@localhost: vx*biwua,8/Q
[root@localhost ~]# 

以获取mysql的root用户的初始密码登录数据库

[root@localhost ~]# mysql -u root -p
Enter password: 

修改root密码

mysql> alter user 'root'@'localhost' identified by '2020root$PWD';
Query OK, 0 rows affected (0.01 sec)

mysql> set global validate_password_length=4;
mysql> set global validate_password_policy=0;
mysql> set password = password("000000");
mysql> update mysql.user set host='%' where user='root';

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> 

允许以root身份远程登录mysql

mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '2020root$PWD' WITH GRANT OPTION;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> 

修改mysql的字符集为utf8
编辑文件/etc/my.conf，设置字符集为utf8

vim /etc/my.cnf

# 增加以下几个设置

[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci

[client]
default-character-set=utf8

重起mysql服务

[root@localhost ~]# service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service
[root@localhost ~]#