SELECT ID拥有最多的ID号 [英] SELECT id HAVING maximum count of id

问题描述

使用item_id和color_id生成产品表。我试图让color_id与最非空的实例。

这样做不成功：

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

与

 群组函数的使用无效
  

$ b $

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

返回 p>

  color_id count 
 1,323 
 2，122 
 3,54 
  

我正在寻找color_id 3，它的实例最多。

解决方案

 <$ c $有没有一种快速简单的方法来获得我想要的内容？ c> SELECT color_id AS id，COUNT（color_id）AS计数
 FROM产品
 WHERE item_id = 1234 AND color_id不为空
 GROUP BY color_id 
 ORDER BY计数DESC 
极限1; 
  

这会为您提供color_id和color_id的计数，顺序由从最大到最小的计数排序。我认为这就是你想要的。

---

为您编辑...

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

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?

解决方案

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;

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