系统环境
[root@centos7 ~]# uname -a
Linux centos7 3.10.0-862.el7.x86_64 #1 SMP Fri Apr 20 16:44:24 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
一、卸载mysql
#查看yum已安装
yum list installed mysql*
#yum卸载已安装
yum remove mysql-community-client mysql-community-common mysql-community-libs mysql-community-libs-compat mysql-community-server mysql57-community-release
rm -rf /var/lib/mysql
rm /etc/my.cnf
#查看rpm安装
rpm -qa | grep -i mysql
#rpm卸载列表
rpm -e mysql57-community-release-el7-9.noarch
cd /var/lib/
rm -rf mysql/
#清除余项
whereis mysql
#删除上面的文件夹
rm -rf /usr/bin/mysql
#删除配置
rm –rf /usr/my.cnf
rm -rf /root/.mysql_sercret
#剩余配置检查
chkconfig --list | grep -i mysql
chkconfig --del mysqld
二、安装mysql
1.进入mysql官网获取RPM包下载地址
#进入mysql官网获取RPM包下载地址https://dev.mysql.com/downloads/repo/yum/
wget https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm
sudo rpm -Uvh mysql80-community-release-el7-3.noarch.rpm
2.查看哪些子存储库已启用或禁用
yum repolist all | grep mysql
3.(方法一)禁用最新GA系列的子存储库并启用特定系列的子存储库
#禁用8.0
sudo yum-config-manager --disable mysql80-community
#启用5.7
sudo yum-config-manager --enable mysql57-community
4.(方法二)手动编辑/etc/yum.repos.d/mysql-community.repo
#找到要配置的子存储库的条目,然后编辑该enabled选项。指定enabled=0禁用子存储库,或enabled=1启用子存储库。要安装MySQL 5.7,请确保MySQL 8.0具有enabled=0,并且MySQL 5.7具有 enabled=1
#注意:当启用多个版本系列的子存储库时,Yum将使用最新的系列
# Enable to use MySQL 5.7
[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
[mysql80-community]
name=MySQL 8.0 Community Server
baseurl=http://repo.mysql.com/yum/mysql-8.0-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
5.验证是否特定子库启用成功
yum repolist enabled | grep mysql
6.安装MySQL服务器的软件包以及其他所需的软件包
sudo yum install mysql-community-server
7.启动MySQL服务器并查看状态
sudo service mysqld start
sudo service mysqld status
#基于EL7的平台
sudo systemctl start mysqld.service
sudo systemctl status mysqld.service
8.查看root临时密码
sudo grep 'temporary password' /var/log/mysqld.log
9.登录并修改密码
mysql -uroot -p
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
--MySQL的 validate_password 插件默认安装。这将要求密码包含至少一个大写字母,一个小写字母,一个数字和一个特殊字符,并且密码总长度至少为8个字符。
10.修改密码策略及长度
set global validate_password_policy=0;
set global validate_password_length=1;
11.修改密码
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';