Linux 安装Mysql1.8【yum安装】

.下载mysql的yum源
wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
2.安装yum源
yum localinstall mysql57-community-release-el7-8.noarch.rpm
3.检查是否安装成功
yum repolist enabled | grep "mysql.*-community.*"

3.安装mysql
yum install mysql-community-server

4.启动服务
systemctl start mysqld
5.设置开机启动
systemctl enable mysqld
systemctl daemon-reload
5.修改root密码
mysql安装完成之后，在/var/log/mysqld.log文件中给root生成了一个默认密码。通过下面的方式找到root默认密码，然后登录mysql进行修改：

5.1 grep 'temporary password' /var/log/mysqld.log

5.2 mysql -uroot -p
输入密码
5.3 
先把5.7之后默认加的密码验证关闭
set global validate_password_policy=0;
set global validate_password_number_count=3;
set global validate_password_length=3;
setglobal validate_password_length=3;
set global validate_password_special_char_count=0;
SHOW VARIABLES LIKE 'validate_password%';
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';

.默认只允许本地连接，需要授权 
grant all privileges on *.* to 'root' @'%' identified by '';
flush privileges;
7.默认配置文件
配置文件：/etc/my.cnf

日志文件：/var/log//var/log/mysqld.log
服务启动脚本：/usr/lib/systemd/system/mysqld.service
socket文件：/var/run/mysqld/mysqld.pid

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setglobal validate_password_length=3;