Getting around the constraint "column must appear in the GROUP BY clause or be used in an aggregate function"
seharusnya seperti ini(supposed to be like this): 

SELECT person.name, person.id, license.expiry_date, COUNT(car) FROM person
  JOIN license ON license.person_id = person.id
  JOIN car ON car.owner_id = person.id
WHERE person.name = 'Charles Bannerman'
GROUP BY person.name, person.id, license.expiry_date, car.car;