MySQL How to Return Unique/Distinct Results?

Question

I\'m running the following MySQL query to find cars that don\'t have manuals (and have black wheels, etc.)

SELECT `cars`.* FROM `cars`
INNER JOIN wheels ON c         


        

Answer 1

add group by cars.id at the end of the query EG:

SELECT `cars`.* FROM `cars`
INNER JOIN wheels ON cars.id = wheels.car_id
LEFT OUTER JOIN manuals ON cars.id = manuals.car_id
WHERE (cars.created_at > '2010-09-09'
    AND wheels.color = 'Black'
    AND wheels.created_at < '2011-01-05'
    AND manuals.car_id IS NULL)
GROUP BY cars.id