linux版本：Centois7

mysql版本：5.7

一、安装

1、下载mysql离线安装包

下载地址：https://dev.mysql.com/downloads/mysql/

选择如下：

【Red Hat Enterprise Linux 7 / Oracle Linux】

【Red Hat Enterprise Linux 7 / Oracle Linux 7 (x86, 64-bit)】

2、上传tar包至服务器

3、删除原有的mariadb

先查看一下是否已经安装了，命令：rpm -qa|grep mariadb

删除mariadb，命令：rpm -e –nodeps mariadb-libs

4、解压缩mysql离线安装包

cd /home/soft

tar -xvf mysql-8.0.16-2.el7.x86_64.rpm-bundle.tar

解压缩之后，包含以下rpm包

mysql-community-libs-8.0.16-2.el7.x86_64.rpm
mysql-community-embedded-compat-8.0.16-2.el7.x86_64.rpm
mysql-community-devel-8.0.16-2.el7.x86_64.rpm
mysql-community-server-8.0.16-2.el7.x86_64.rpm
mysql-community-libs-compat-8.0.16-2.el7.x86_64.rpm
mysql-community-client-8.0.16-2.el7.x86_64.rpm
mysql-community-common-8.0.16-2.el7.x86_64.rpm
mysql-community-test-8.0.16-2.el7.x86_64.rpm

5、安装rmp包

逐个安装，命令如下：

【必须安装】

rpm -ivh mysql-community-common-8.0.16-2.el7.x86_64.rpm

rpm -ivh mysql-community-libs-8.0.16-2.el7.x86_64.rpm

rpm -ivh mysql-community-client-8.0.16-2.el7.x86_64.rpm

rpm -ivh mysql-community-server-8.0.16-2.el7.x86_64.rpm

【非必须安装】

rpm -ivh mysql-community-libs-compat-8.0.16-2.el7.x86_64.rpm

rpm -ivh mysql-community-embedded-compat-8.0.16-2.el7.x86_64.rpm

rpm -ivh mysql-community-devel-8.0.16-2.el7.x86_64.rpm

rpm -ivh mysql-community-test-8.0.16-2.el7.x86_64.rpm

出现错误1：

warning: mysql-community-devel-8.0.16-2.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
error: Failed dependencies:
    pkgconfig(openssl) is needed by mysql-community-devel-8.0.16-2.el7.x86_64

解决办法1：

yum install openssl-devel.x86_64 openssl.x86_64 -y

出现问题2：

warning: mysql-community-test-8.0.16-2.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
error: Failed dependencies:
    perl(Data::Dumper) is needed by mysql-community-test-8.0.16-2.el7.x86_64
    perl(JSON) is needed by mysql-community-test-8.0.16-2.el7.x86_64

解决办法2：

yum install perl.x86_64 perl-devel.x86_64 -y

yum install perl-JSON.noarch -y

yum -y install autoconf

二、服务启停

1、查看服务状态

命令：systemctl status mysqld

2、停止服务

命令：service mysqld stop

3、初始化数据库

命令：mysqld –initialize –console

4、目录授权

命令：chown -R mysql:mysql /var/lib/mysql/

5、启动mysql服务

命令：systemctl start mysqld

命令：systemctl status mysqld

三、数据库操作

1、查看临时密码：

命令：cat /var/log/mysqld.log

2、用临时密码登录数据库

命令：mysql -u root -p 回车键

然后输入临时密码（输入时不会显示出来，输入完直接回车）

3、修改mysql密码

命令：alter USER ‘root’@’localhost’ IDENTIFIED BY ‘123456’;

4、授权远程连接

命令：show databases;

命令：use mysql;

命令：select host, user, authentication_string, plugin from user;

命令：update user set host = “%” where user=’root’;

命令：select host, user, authentication_string, plugin from user;

命令：flush privileges;

尝试使用navacat远程连接，会出现如下错误

2059 - Authenticationplugin‘caching_sha2_password’ cannot be loaded:XXXXX

解决办法：

命令：mysql -u root -p（回车后，输入更改后的密码123456）

命令：use mysql;

命令：alter USER ‘root’@’%’ IDENTIFIED WITH mysql_native_password BY ‘123456’;

命令：flush privileges;

备注：
mysql8 之前的版本中加密规则是mysql_native_password，而在mysql8之后,加密规则是caching_sha2_password。
解决问题方法有两种：
方法1.升级navicat驱动；
方法2.把mysql用户登录密码加密规则还原成mysql_native_password.。
此处我使用的是方法2。

再次从navicat尝试连接mysql，测试成功。