SELECT
    pet.name,
    person.first_name,
    person.last_name,
    person_pet.purchased_on
FROM pet, person, person_pet
WHERE
    person_pet.purchased_on >= DATETIME('2004-01-01 00:00:00')
    AND person_pet.pet_id = pet.id
    AND person_pet.person_id = person.id;

SELECT pet.name
FROM pet, person
WHERE pet.parent = person.id
    AND person.first_name = 'Zed';