DROP TABLE ema_pets;
CREATE TABLE ema_pets(pet_id int, name text, dob date, type text, 
		      PRIMARY KEY(pet_id));

DROP TABLE ema_vet_visit;
CREATE TABLE ema_vet_visit(pet_id int, when date, disc text, cost int, 
			   FOREIGN KEY(pet_id) REFERENCES ema_pets, 
			   PRIMARY KEY(pet_id, date));

INSERT INTO ema_pets VALUES(01, 'libby', 01/01/90, 'dog');
INSERT INTO ema_pets VALUES(02, 'joe', 01/02/91, 'cat');
INSERT INTO ema_pets VALUES(007, 'jane', 01/03/91, 'chicken');

INSERT INTO ema_vet_visit VALUES(01, 01/01/91, 'year_check_up', 200);
INSERT INTO ema_vet_visit VALUES(02, 01/02/92, 'year_check_up', 200);
INSERT INTO ema_vet_visit VALUES(007, 12/01/91, 'plucking', 10);
INSERT INTO ema_vet_visit VALUES(01, 01/01/92, '2year_check_up', 300);
INSERT INTO ema_vet_visit VALUES(02, 01/02/93, '2year_check_up', 300);
INSERT INTO ema_vet_visit VALUES(01, 01/01/93, '3year_check_up', 600);