腾讯云服务器是没有预先安装mysql的,
服务器上的安装命令和本机的感觉不一样(忧伤)
安装命令:sudo apt-get install mysql-server(不是 sudo apt-get install mysql/mysqld)
创建用户:create user username identified by '123456';
赋予所有权限:grant all on *.* to 'username' @'%' identified by '123456';
删除用户:DELETE FROM mysql.user WHERE User="phplamp" and Host="localhost";