CREATE TABLE client ( client_id varchar2(20)primary key, client_password varchar2(16)NOT NULL, client_nickname varchar2(30) unique NOT NULL, client_grade varchar2(9) NOT NULL check(client_grade in ('일반','우수','관리자','VIP')), client_join date default sysdate NOT NULL, client_point number default 0 NOT NULL check(client_point >= 0) ); DROP table client ; CREATE TABLE item ( item_no number primary ke..