Question

I have some sql that gathers product information. It also retrieves images from joined tables. Sometimes a product will have more than one image (sometimes none) and this causes duplicates in the results. How can I change this query to only return a single image (or no images) from the joined image tables – image_d,image_p,image_t ?

SELECT 
   products_categories.categoryid, 
   products.productid, 
   products.product, 
   products.descr, 
   products.rating, 
   products.title_tag, 
   images_d.image_path AS imaged, 
   images_p.image_path AS imagep, 
   images_t.image_path AS imaget, 
   clean_urls.clean_url 
FROM products_categories 
INNER JOIN products ON products_categories.productid = products.productid 
LEFT JOIN images_d ON products.productid = images_d.id 
LEFT JOIN images_p ON products.productid = images_p.id 
LEFT JOIN images_t ON products.productid = images_t.id 
LEFT JOIN clean_urls ON products.productid = clean_urls.resource_id 
WHERE  products_categories.categoryid = 265 
AND products_categories.main = 'Y' 
AND products.forsale = 'Y'
ORDER  BY productid 

Thanks.

Answer 1

I assume that there’s more than one image in a given image_x table. You can use group_concat() to shoehorn multiple values into one CSV column:

SELECT
   products_categories.categoryid, 
   products.productid, 
   products.product, 
   products.descr, 
   products.rating, 
   products.title_tag, 
   group_concat(images_d.image_path) AS imaged, 
   group_concat(images_p.image_path) AS imagep, 
   group_concat(images_t.image_path) AS imaget, 
   clean_urls.clean_url 
FROM products_categories 
INNER JOIN products ON products_categories.productid = products.productid 
LEFT JOIN images_d ON products.productid = images_d.id 
LEFT JOIN images_p ON products.productid = images_p.id 
LEFT JOIN images_t ON products.productid = images_t.id 
LEFT JOIN clean_urls ON products.productid = clean_urls.resource_id 
WHERE products_categories.categoryid = 265 
AND products_categories.main = 'Y'
AND products.forsale = 'Y'
GROUP BY 1,2,3,4,5,6,10
ORDER BY productid