SELECT id HAVING maximum count of id

a coder picture a coder · Jan 10, 2013 · Viewed 66.7k times · Source

Have a products table with item_id and color_id. I'm trying to get the color_id with the most non-null instances.

This fails:

SELECT color_id 
  FROM products 
 WHERE item_id=1234 
 GROUP BY item_id 
HAVING MAX(COUNT(color_id))

with

Invalid use of group function

This

SELECT color_id, COUNT(color_id)
  FROM products 
 WHERE item_id=1234 
 GROUP BY item_id

Returns

color_id count
1, 323
2, 122
3, 554

I am looking for color_id 3, which has the most instances.

Is there a quick and easy way of getting what I want without 2 queries?

Answer

matt walters picture matt walters · Jan 10, 2013
SELECT color_id AS id, COUNT(color_id) AS count 
FROM products 
WHERE item_id = 1234 AND color_id IS NOT NULL 
GROUP BY color_id 
ORDER BY count DESC
LIMIT 1;

This will give you the color_id and the count on that color_id ordered by the count from greatest to least. I think this is what you want.


for your edit...

SELECT color_id, COUNT(*) FROM products WHERE color_id = 3;