create table guest(num smallint auto_increment primary key, myid varchar(20), content varchar(2000), photoname varchar(50), chu smallint default 0, writeday datetime) create table answer (idx smallint auto_increment primary key, num smallint references guest(num) on delete cascade, myid varchar(20), content varchar(1000), writeday datetime) 왜 idx로 smallint를 하냐면 guest에 이미 num을써서. 겹치면 안되서 idx로 작성 ..