selecting the least value in a joined table - mysql

Question

Basically I have product and several models for those products. Each model has a price.
This is what I intended to do:
Mark a product as featured, then have it's title, description, number 1 image's thumbnail and the price for the cheapest model
This is my current query:
SELECT
product.title,
product.url_name,
product.description,
price.price,
image.thumbnail
FROM
mps_contents AS product
LEFT OUTER JOIN
mps_contents AS image
ON
image.page_id = product.content_id AND
image.display_order = '1' AND
image.resource_type = 'image'
LEFT OUTER JOIN
mps_contents AS model
ON
product.content_id = model.page_id
INNER JOIN
mps_product_info AS price
ON
model.content_id = price.content_id
WHERE
product.active = '1' AND
product.resource_type = 'product' AND
product.featured = '1'
ORDER BY RAND( )
LIMIT 3
You may see that my query cannot do the price sorting, I hope somebody could help me with that. An additional problem that I encounter is if I have multiple models for a product. I end up getting a set that has prices for 2 models from a single product when the intent is to have the 1 price for each product.
I am aware of the issue with ORDER BY RAND() but I will ignore it since I don't think this site will have more that 50 products.

Answer 1

I think something like this should work....
SELECT
product.title,
product.url_name,
product.description,
A.price,
image.thumbnail
FROM
mps_contents AS product
LEFT OUTER JOIN
mps_contents AS image
ON
image.page_id = product.content_id AND
image.display_order = '1' AND
image.resource_type = 'image'
LEFT OUTER JOIN (
SELECT price.price
FROM mps_contents AS model
JOIN mps_product_info price ON (model.content_id = price.content_id)
WHERE model.page_id = product.content_id
ORDER BY price.price
LIMIT 1
) AS A
WHERE
product.active = '1' AND
product.resource_type = 'product' AND
product.featured = '1'
ORDER BY RAND( )
LIMIT 3