Question

So I have been trying this for over a week and a bit, I put it to rest because I couldn’t get it to work but this is what I am trying to do;

Select a product from the database > Use LEFT OUTER JOIN to load its rating and make an average of it > Use INNER JOINs for different information (not really important, but I will say it anyway).

This is a simplified (but accurate) replica of my query – the original is quite long and has different language words in it so it might get a bit confusing;

SELECT 
PRODUCT.name AS Name,
PRODUCT.price AS Price,
BRAND.name AS Brand,
AVG(RATING.rating) AS Rating
FROM PRODUCT
LEFT OUTER JOIN RATING ON RATING.product_id = PRODUCT.product_id
INNER JOIN BRAND ON BRAND.brand_id = PRODUCT.brand_id
GROUP BY PRODUCT.name, PRODUCT.price, BRAND.name

The above works, but it misses the ‘filtering’ on rating.
I wish adding WHERE AVG(RATING.rating) > 3 would work, but sadly it doesn’t.
Is this in any way possible to do?

Thanks.

Answer 1

Try HAVING AVG(RATING.rating) > 3 after your GROUP BY.

See HAVING on MSDN for more details.