查询当前db：1 select database() 2 status 3 show tables

CREATE USER 'pig'@'%' IDENTIFIED BY '';
use mysql
create user 'lych'@'%' identified by 'lych00';(%,IP,localhost)
create database lych;
grant all on . to lych;(grant all privileges on lych to lych@'%')
show grants for lych

---待续