3，mysql基础

centos7安装MYSQL5.7:

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wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm
sudo yum -y install mysql57-community-release-el7-10.noarch.rpm
sudo yum install mysql-community-server
service mysqld start
service mysqld stop
service mysqld status

默认密码问题：

cat /var/log/mysqld.log | grep 'password'
mysql -uroot -p<password>   #使用上一步获得的 password
ALTER USER 'root'@'localhost' IDENTIFIED BY 'Li-059118';
exit;

sudo vim /etc/my.cnf
#添加validate_password_policy配置
validate_password_policy=0
#关闭密码策略
validate_password = off

#修改mysql字符编码
[mysqld]    
character_set_server=utf8
init_connect='SET NAMES utf8'

service mysqld restart
mysql -uroot -p<password>
set password for root@localhost = password('059118');

show variables like '%password%'; #查看密码策略
show variables like '%character%'; #查看字符编码

开启远程访问：

grant all privileges on *.* to 'root'@'<ip地址>' identified by 'password' with grant option;
flush privileges;
exit;

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ubuntu18安装MYSQL5.7:

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sudo apt install mysql-server
sudo apt install mysql-client
*sudo apt install libmysqlclient-dev    #程序编译时链接的库
service mysql start
service mysql stop
service mysql status

默认密码问题：

sudo cat /etc/mysql/debian.cnf  #查看：<password>
mysql -u debian-sys-maint -p<password>
show databases;
use mysql;
update user set authentication_string=password('1234') where user='root';
update user set plugin='mysql_native_password';
flush privileges;
quit;
service mysql restart