linux快速安装mysql

安装之前检测系统是否有自带的MySQL

#检查是否安装过MySQL
rpm -qa | grep mysql 
#检查是否存在 mariadb 数据库（内置的MySQL数据库），有则强制删除
rpm -qa | grep mariadb 
#强制删除
rpm -e --nodeps mariadb-libs-5.5.68-1.el7.x86_64
#强制删除
rpm -e --nodeps mariadb-5.5.68-1.el7.x86_64

导入密钥

rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

配置MySQL的yum仓库

rpm -Uvh http://repo.mysql.com//mysql57-community-release-el7-7.noarch.rpm

使用yum安装mysql
```
yum -y install mysql-community-server
```
启动mysql
```
systemctl start mysqld
```
查看MySQL状态
```
systemctl status mysqld
```
设置为开机自启
```
systemctl enable mysqld
```

获取MySQL初始密码

cat /var/log/mysqld.log |grep "temporary password"

登录mysql数据库
```
mysql -u root -p 
```
修改root用户命令(密码有要求不低于8位,有大小写,有特殊字符)
```
alter user 'root'@'localhost' identified by 'rootRoot123.';
```

设置简单密码(把校验策略改成低/把密码校验长度改低一点

set global validate_password_policy=LOW;
set global validate_password_length=4;
alter user 'root'@'localhost' identified by '123456';

设置远程访问

grant all privileges on *.* to 'root' @'%' identified by '123456';flush privileges;

卸载

#强制删除已安装MySQL
rpm -e --nodeps mysql-community-libs
rpm -e --nodeps mysql-community-client
rpm -e --nodeps mysql-community-server
rpm -e --nodeps mysql57-community-release
rpm -e --nodeps mysql-community-common
rpm -qa|grep mysql#查找所有MySQL目录并删除：find / -name mysql 
find / -name mysql
find: ‘/proc/35432’: 没有那个文件或目录
#/var/lib/mysql
#/var/lib/mysql/mysql
#/usr/lib64/mysql
#/usr/share/mysql
rm -rf /var/lib/mysql
rm -rf /usr/share/mysql
rm -rf /usr/lib64/mysql