下载

一、官方下载地址

https://downloads.mysql.com/archives/community/

将下载的安装上传到CentOS7虚拟机系统中某一目录下。

当然也可以登录进入CentOS7虚拟机系统内通过wget下载（不过不建议采用种方式，主要是安装包有些大）

[root@localhost ~]# wget https://downloads.mysql.com/archives/get/p/23/file/mysql-5.7.21-1.el7.x86_64.rpm-bundle.tar

二、安装

1. 卸载系统自带的 mariadb-lib

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

2. 安装我们下载好的Mysql5.7

   进入我们下载Mysql5.7安装包所在目录

   [root@localhost ~]# 
   [root@localhost ~]# ls
   anaconda-ks.cfg  mysql-5.7.21-1.el7.x86_64.rpm-bundle.tar
   

   然后解压

   [root@localhost ~]# ls
   anaconda-ks.cfg  mysql-5.7.21-1.el7.x86_64.rpm-bundle.tar
   [root@localhost ~]# tar -xvf mysql-5.7.21-1.el7.x86_64.rpm-bundle.tar
   

   依次执行下面安装命令

   rpm -ivh mysql-community-common-5.7.21-1.el7.x86_64.rpm
   rpm -ivh mysql-community-libs-5.7.21-1.el7.x86_64.rpm
   rpm -ivh mysql-community-client-5.7.21-1.el7.x86_64.rpm
   rpm -ivh mysql-community-server-5.7.21-1.el7.x86_64.rpm
   rpm -ivh mysql-community-libs-compat-5.7.21-1.el7.x86_64.rpm
   

   以安全模式初始化mysql

   mysqld --initialize --user=mysql
   

   查看 初始化密码

   [root@localhost ~]# grep "password" /var/log/mysqld.log 
   2020-05-26T04:08:07.475037Z 1 [Note] A temporary password is generated for root@localhost: y&F6MP<hhlSf
   

   启动Mysql并检查其服务状态

   [root@localhost ~]# systemctl start mysqld
   [root@localhost ~]# systemctl status mysqld
   ● mysqld.service - MySQL Server
      Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
      Active: active (running) since 二 2020-05-26 12:10:02 CST; 4s ago
        Docs: man:mysqld(8)
              http://dev.mysql.com/doc/refman/en/using-systemd.html
     Process: 2434 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
     Process: 2417 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
    Main PID: 2437 (mysqld)
      CGroup: /system.slice/mysqld.service
              └─2437 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
   
   5月 26 12:10:02 localhost.localdomain systemd[1]: Starting MySQL Server...
   5月 26 12:10:02 localhost.localdomain systemd[1]: Started MySQL Server.
   

   设置 mysql 服务自启动

   [root@localhost ~]# systemctl enable mysqld
   // 设置完成后，通过下面代码查看是否设置成功
   [root@localhost ~]# systemctl list-unit-files --type=service | grep mysqld
   mysqld.service                                enabled 
   mysqld@.service                               disabled
   

3. 修改初始化密码

   查看初始化密码

   [root@localhost ~]# grep "password" /var/log/mysqld.log
   2020-05-26T04:08:07.475037Z 1 [Note] A temporary password is generated for root@localhost: y&F6MP<hhlSf
   

   使用初始化密码登入mysql

   [root@localhost ~]# mysql -uroot -p
   Enter password: 
   Welcome to the MySQL monitor.  Commands end with ; or \g.
   Your MySQL connection id is 3
   Server version: 5.7.21
   
   Copyright (c) 2000, 2018, 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> show databases;
   ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
   mysql>
   

   修改初始化密码

   mysql> alter user 'root'@'localhost' identified by 'root';
   Query OK, 0 rows affected (0.00 sec)
   
   mysql> show databases;
   +--------------------+
   | Database           |
   +--------------------+
   | information_schema |
   | mysql              |
   | performance_schema |
   | sys                |
   +--------------------+
   4 rows in set (0.00 sec)
   

   Mysql安装完成

三、开始使用

使用修改后的密码，正式登录使用Mysql

[root@localhost ~]# mysql -uroot -proot
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.21 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, 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> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

mysql>

修改 root 登录限制为允许开放所有登录方式（远程登录）

mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select user,host from user;
+---------------+-----------+
| user          | host      |
+---------------+-----------+
| mysql.session | localhost |
| mysql.sys     | localhost |
| root          | localhost |
+---------------+-----------+
3 rows in set (0.00 sec)

mysql> update user set host = '%' where user = 'root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

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

mysql>

远程客户端登录测试