SELECT id HAVING maximum count of id

Question

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?

Solution 1

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;

Solution 2

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

UPDATE 1

SELECT  color_id, COUNT(color_id) totalCount
FROM    products 
WHERE   item_id = 1234 
GROUP   BY color_id 
HAVING  COUNT(color_id) =
(
  SELECT  COUNT(color_id) totalCount
  FROM    products 
  WHERE   item_id = 1234 
  GROUP   BY color_id 
  ORDER BY totalCount DESC
  LIMIT 1  
)

• SQLFiddle Demo (having tie)

Solution 3

SELECT 
  color_id, 
  COUNT(color_id) AS occurances
FROM so_test
GROUP BY color_id
ORDER BY occurances DESC
LIMIT 0, 1

Here is a sample fiddle with a basic table that shows it working: sql fiddle

Comments

[Gordon Linoff]

You should add a limit 1 to answer the question.

[John Woo]

@GordonLinoff limit 1. what if there are multiple instances having the same greatest count?

[John Woo]

consider this result, 1, 100, 2, 100, 3, 50.

[matt walters]

@JW Depeneds on the context. maybe you don't care if there are ties for the max... maybe you do...

[a coder]

I think this would be a logic problem on my end.. what to show.

[a coder]

I need to assign an importance to each color_id and let that be the tie breaker.

[VishalParkash]

fantastic, this is what I was looking for,