关闭外键检查：
SET FOREIGN_KEY_CHECKS = 0
创建新用户
grant all on dbname.tablename to username@hostname identified by 'password';
删除记录
delete from tablename where id='';
更新记录
update tablename set id='' where id='';
查看数据库连接情况：
show processlist;
查看数据库情况：
SHOW GLOBAL STATUS
备份数据库
mysqldump -uusernmae -ppassword dbname > dbname.sql
还原数据库
mysql -uusernmae -ppassword dbname