CREATE USER 'username'@'host' IDENTIFIED BY 'password';
比如
create user 'test_user'@'%' identified by 'test';
ps：如果只允许本机登录则host=localhost，如果允许从任意远程主机登陆则host=%
修改密码
SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');
2 授权
GRANT privileges ON dbname.tablename TO 'username'@'host'
比如
GRANT ALL ON test_db.* TO 'test_user'@'%';
撤销权限
REVOKE privilege ON dbname.tablename FROM 'username'@'host';
3 查看某个用户的授权
show grants for test_user;
4 数据导出
$ mysqldump -u dbuser -p dbname [tablename1] [tablename2] > dump.sql
ps：tablename可选
如果想导出所有database，dataname处传 --all-databases
更多参数：
--no-create-info 不导出建表语句
--skip-add-locks 跳过锁表语句
--where="..." 只导出满足条件的数据
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;