Centos7安装/卸载MySQL8
目录
- 1 卸载MySQL
-
- 1.1 关闭服务
- 1.2 卸载MySQL
- 1.3 删除MySQL相关文件
- 2 安装MySQL
-
- 2.1 下载安装包
- 2.2 检查依赖
- 2.3 安装
- 2.4 初始化
- 2.5 允许远程连接
-
- 2.5.1 centos7允许访问端口
- 2.5.2 MySQL允许用户远程登录
1 卸载MySQL
1.1 关闭服务
查看是否安装过MySQL
rpm -qa | grep -i mysql
检查MySQL service
systemctl status mysqld
关闭MySQL服务
systemctl stop mysqld
1.2 卸载MySQL
查看当前MySQL安装情况
rpm -qa | grep -i mysql
# 或
yum list installed | grep mysql
卸载上述命令查询出的已安装程序
yum remove -y mysql-xxxx mysql-xxxx
1.3 删除MySQL相关文件
查找相关文件
find / -name mysql
删除
rm -rf /usr/lib64/mysql
删除 my.cnf
rm -rf /etc/my.cnf
2 安装MySQL
2.1 下载安装包
https://dev.mysql.com/downloads/mysql/
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解压后选择需要用的安装包上传至Centos
mysql-community-client-8.0.25-1.el7.x86_64.rpm
mysql-community-client-plugins-8.0.25-1.el7.x86_64.rpm
mysql-community-common-8.0.25-1.el7.x86_64.rpm
mysql-community-libs-8.0.25-1.el7.x86_64.rpm
mysql-community-server-8.0.25-1.el7.x86_64.rpm
2.2 检查依赖
检查/tmp目录权限
chmod -R 777 /tmp
检查依赖
rpm -qa | grep libaio
rpm -qa | grep net-tools
2.3 安装
按顺序执行
rpm -ivh mysql-community-common-8.0.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-plugins-8.0.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.0.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.0.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.0.25-1.el7.x86_64.rpm
执行rpm -ivh mysql-community-libs-8.0.25-1.el7.x86_64.rpm时报错
错误：依赖检测失败：
mariadb-libs 被 mysql-community-libs-8.0.25-1.el7.x86_64 取代
解决办法：执行
yum -y remove mysql-libs
查看MySQL版本
mysql --version
rpm -qa | grep -i mysql
2.4 初始化
服务的初始化
为了保证数据库目录与文件的所有者为mysql登录用户，如果是以root身份运行mysql服务，需执行下面命令初始化
mysqld --initialize --user=mysql
说明：–initialize选项默认以安全模式初始化，会为root用户生成一个密码并将该密码标记为过期，登录后需要设置一个新的密码。生成的临时密码会在日志中记录一份。
查看密码
cat /var/log/mysqld.log
root@localhost:后面为初始密码
检查MySQL服务是否启动
systemctl status mysqld
启动MySQL服务
systemctl start mysqld
检查MySQL服务是否启动
systemctl status mysqld
查看MySQL服务是否自启动
systemctl list-unit-files | grep mysqld.service
若不是enabled，执行如下命令设置自启动
systemctl enable mysqld.service
登录MySQL
mysql -uroot -p
输入初始密码即可。
show databases;报错
mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
修改密码
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
退出MySQL Client，使用新密码重新登录即可。
2.5 允许远程连接
2.5.1 centos7允许访问端口
方式一：关闭防火墙
查看防火墙状态
systemctl status firewalld
关闭防火墙
systemctl stop firewalld
关闭防火墙自启动
systemctl disable firewalld
方式二：开放端口
查看开放的端口号
firewall-cmd --list-all
设置开放端口号
firewall-cmd --add-service=http --permanent
firewall-cmd --add-port=3306/tcp --permanent
重启防火墙
firewall-cmd --reload
2.5.2 MySQL允许用户远程登录
use mysql;
select host,user from user;
update user set host='%' where user = 'root';
flush privileges;
如果报错
Plugin caching_sha2_password could not be loaded;
MySQL执行
mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';