CREATE TABLE animals (
    id serial PRIMARY KEY ,
    name VARCHAR(30) NOT NULL ,
    birthdate DATE NOT NULL ,
    owner_id INTEGER,
    animal_type_id INTEGER NOT NULL ,

    CONSTRAINT fk_animals_owners
        FOREIGN KEY (owner_id)
        REFERENCES owners(id)
        ON DELETE CASCADE
        ON UPDATE CASCADE,

    CONSTRAINT fk_animals_animal_types
        FOREIGN KEY (animal_type_id)
        REFERENCES animal_types(id)
        ON DELETE CASCADE
        ON UPDATE CASCADE
);