"pet_id" int,
"person_id" int
constraint fk_person_id references person(person_id) on update CASCADE on delete RESTRICT,
+ "person_id_2" int
+ constraint fk_person_id_2 references person(person_id) on update SET NULL on delete SET DEFAULT,
+ "person_id_3" int
+ constraint fk_person_id_3 references person(person_id) on update NO ACTION,
"name" varchar(30),
"age" int,
constraint age_under_100 check ( age < 100 ),