centos 安装mysql8

一、卸载旧版本

1、查看mysql安装了哪些东西

[root@iZuf65saybbvavxkh38cdiZ mysql]# rpm -qa |grep -i mysql
mysql80-community-release-el8-1.noarch
mysql-community-server-8.0.27-1.el8.x86_64
mysql-community-client-plugins-8.0.27-1.el8.x86_64
mysql-community-libs-8.0.27-1.el8.x86_64
mysql-community-client-8.0.27-1.el8.x86_64
bt-mysql57-5.7.34-1.el8.x86_64
mysql-community-common-8.0.27-1.el8.x86_64
[root@iZuf65saybbvavxkh38cdiZ mysql]# 

2、通过yum remove 将以上内容删除

yum remove mysql80-community-release-el8-1.noarch
yum remove mysql-community-server-8.0.27-1.el8.x86_64
yum remove mysql-community-client-plugins-8.0.27-1.el8.x86_64
yum remove mysql-community-libs-8.0.27-1.el8.x86_64
yum remove mysql-community-client-8.0.27-1.el8.x86_64
yum remove bt-mysql57-5.7.34-1.el8.x86_64
yum remove mysql-community-common-8.0.27-1.el8.x86_64

3、检查是否卸载干净

rpm -qa |grep -i mysql

4、查找mysql相关目录

[root@iZuf65saybbvavxkh38cdiZ mysql]# find / -name mysql
find: ‘/proc/29250/task/29250/net’: Invalid argument
find: ‘/proc/29250/net’: Invalid argument
/etc/logrotate.d/mysql
/var/lib/selinux/targeted/active/modules/100/mysql
/var/lib/selinux/targeted/tmp/modules/100/mysql
/var/lib/mysql
/var/lib/mysql/mysql
/usr/bin/mysql
/usr/lib64/mysql
/usr/share/selinux/targeted/default/active/modules/100/mysql

5、同时对这些目录进行删除

rm -rf /etc/logrotate.d/mysql
rm -rf /var/lib/selinux/targeted/active/modules/100/mysql
rm -rf /var/lib/selinux/targeted/tmp/modules/100/mysql
rm -rf /var/lib/mysql
rm -rf /var/lib/mysql/mysql
rm -rf /usr/bin/mysql
rm -rf /usr/lib64/mysql
rm -rf /usr/share/selinux/targeted/default/active/modules/100/mysql

6、删除/etc/my.cnf 文件rm -rf /etc/my.cnf

7、删除 /var/log/mysql/mysqld.log文件。rm -rf /var/log/mysql/mysqld.log

完成以上内容则卸载完成mysq

二、卸载 mariadb

1、查看是否有安装 mariadb，该软件与 MySQL 数据库有冲突，需要手动卸载

# 如果是 CentOS7 可以检测出已经安装了 mariadb
rpm -qa | grep mariadb

2、删除 mariadb

rpm -e --nodeps mariadb-libs-5.5.68-1.el7.x86_64

三、安装

1、进入MySQL官网 >> downloads >> MySQL Community(GPL)Downloads

点击MySQL Community Server 

2、根据自己的服务器架构和Linux版本选择软件

//查看Linux架构
uname -m

3、下载到自己安装的路径下

mkdir /home/softwore/mysql
cd /home/softwore/mysql
wegt https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.4.2-1.el7.x86_64.rpm-bundle.tar

4、解压

tar -xvf mysql-8.0.35-1.el8.x86_64.rpm-bundle.tar

5、使用 rpm 安装

必须按照顺序执行命令，否则会出现依赖错误的报错

rpm -ivh mysql-community-common-8.4.2-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-plugins-8.4.2-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.4.2-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.4.2-1.el7.x86_64.rpm
rpm -ivh mysql-community-icu-data-files-8.4.2-1.el7.x86_64.rpm
rpm -ivh mysql-community-devel-8.4.2-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.4.2-1.el7.x86_64.rpm

问题1：

解决方案：

yum install openssl-devel

问题2：

解决方案：

yum install net-tools
yum install -y perl-Module-Install.noarch

6、查看已安装的 MySQL 的版本

mysql --version

7、配置my.cof

设置,表名不区分大小写，在[mysqld]下加入一行：lower_case_table_names=1

8、修改安装目录的所有者/所属组,使用户拥有访问MySQL文件夹的权限

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

9、初始化

mysqld --initialize --console

10、启动mysql

#开机自启
systemctl enable mysqld
#启动
systemctl start mysqld
#查看状态
systemctl status mysqld
#重启
systemctl restart mysqld
#关闭
systemctl stop mysqld
#关闭开机自启
systemctl disable mysqld

11、获取 root 用户的初始密码

cat /var/log/mysqld.log | grep root@localhost