【原创】数据库基础之Mysql（1）经常使用命令

1 建立用户

CREATE USER 'username'@'host' IDENTIFIED BY 'password';

好比

create user 'test_user'@'%' identified by 'test';

ps：若是只容许本机登陆则host=localhost，若是容许从任意远程主机登录则host=%

修改密码

SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');

2 受权

GRANT privileges ON dbname.tablename TO 'username'@'host'

好比

GRANT ALL ON test_db.* TO 'test_user'@'%';

撤销权限

REVOKE privilege ON dbname.tablename FROM 'username'@'host';

3 查看某个用户的受权

show grants for test_user;

4 数据导出

$ mysqldump -u dbuser -p dbname [tablename1] [tablename2] > dump.sql

ps：tablename可选

若是想导出全部database，dataname处传 --all-databases

5 数据导入

mysql>source /path/dump.sql

或者

$ mysql -uusername -p dbname < dump.sql

6 定位问题

mysql>show processlist;

mysql>show variables;

7 修改字符集

mysql> alter database $database_name character set utf8;mysql> alter table $table_name default character set utf8;mysql> alter table $table_name change $column_name $column_name varchar(50) character utf8;