rendered paste bodycreate table Tguestbooks ( id serial primary key, name varchar(264) not null unique, user_id integer not null, date_cr timestamp default now() not null, moderation integer not null, foreign key (user_id) references Tusers};create table Tguestbooks_message ( id serial primary key, guestbook_id integer not null, user_question_id integer not null, user_answer_id integer, question text, answer text, date_question timestamp default now() not null, date_answer timestamp, foreign key (user_id) references Tusers foreign key (unit_id) references Tguestbooks);