ubuntu安装mysql教程

一.首先卸载掉原来的mysql

第一步，依次执行下面的语句

sudo apt-get autoremove --purge mysql-server
sudo apt-get remove mysql-server
sudo apt-get autoremove mysql-server
sudo apt-get remove mysql-common 

第2步 清理残留数据

dpkg -l |grep ^rc|awk '{print $2}' |sudo xargs dpkg -P

二.安装mysql

安装mysql教程
sudo aptitude search  mysql
sudo apt install  mysql-server

登录mysql

sudo mysql -u root -p
show databases;

use mysql;

show tables;
select host,user from user;
#添加登录账号,允许远程访问'%'
grant all privileges on *.* to 'admin'@'%' identified by 'pass12345xx' with grant option;

注意：如果报 ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '. to 'admin'@'%'' at line 1

提示意思是不能用grant创建用户，mysql8.0以前的版本可以使用grant在授权的时候隐式的创建用户，8.0以后已经不支持，所以必须先创建用户，然后再授权，命令如下：

 CREATE USER 'admin'@'%' IDENTIFIED BY 'pass12345xx';

 grant all privileges on *.* to 'admin'@'%';

允许多个IP登录mysql8.0

# 第一个IP

CREATE user 'admin'@'121.43.128.209' IDENTIFIED by 'pass12345xx';
GRANT ALL on *.* TO 'admin'@'121.43.128.xxx';
flush privileges;

# 第二个IP

CREATE user 'admin'@'139.224.43.133' IDENTIFIED by 'pass12345xx';
GRANT ALL on *.* TO 'admin'@'139.224.43.xxx';
flush privileges;

# 有几个IP，就创建多少个用户

修改允许的ip

UPDATE `user` SET `Host`='172.0.0.1' WHERE `user`='admin' AND `Host`='175.9.142.131';
flush privileges;

如果要删除某个IP权限

delete from user where host ='172.0.0.2';

如果存在用户，修改用户密码，

例如：修改root用户的密码为Root12###2

alter user 'root'@'%' identified by 'Root12###2';
flush privileges;

删除用户：

DROP USER '需要删除的账户'@'连接来源';

drop user admin@localhost;

例如：删除用户admin

drop user 'admin'@'%';

#刷新
flush privileges;
quit;
#重启
sudo service mysql restart;
#查看mysql版本
mysql -V

第三步  设置MySQL远程访问的权限 
aptitude search  mysql.conf.d
cd /etc/mysql/mysql.conf.d
ls
#查看目录下所有的文件内容，找到bind-address = 127.0.0.1注释掉
sudo vim mysqld.cnf
加前缀#注释掉bind-address = 127.0.0.1

重启mysql
sudo service mysql restart;

最后重新登录mysql

mysql -u root -p

另外：

修改密码
update mysql.user set password=password('新密码') where User="amdin" ;

mysql查看端口号
show variables like 'port';

删除登录用户

DROP USER IF EXISTS admin;