從GROUP BY獲取MAX

Question

當我遇到這個時，我正在練習一些SQL。 我想知道某種商品出現了多少次，從那里獲得了最多的商品。

這表明每種商品出現的次數：

mysql> SELECT commodity, COUNT(commodity) count FROM orders GROUP BY commodity ORDER BY count;
+----------------------+------------+
| commodity            |    count   |
+----------------------+------------+
| PERSIAN MELON        |          4 |
| BEANS                |          6 |
| CASABA               |         10 |
| ASPARAGUS            |         11 |
| EGGPLANT             |         12 |
| TOMATOES, CHERRY     |         16 |
| GALIA MELON          |         18 |
+-----------------------------------+

我試圖得到最高的行，但這都是錯的：

mysql> SELECT commodity, MAX(COUNT(commodity)) count FROM orders GROUP BY commodity ORDER BY count;

這樣做的正確方法是什么？

Answer 1

注意：查詢不會處理具有最大COUNT重復記錄

SELECT  commodity,  COUNT(commodity) `count` 
FROM    orders 
GROUP   BY commodity
ORDER   BY `count` DESC 
LIMIT   1

但是這會，

SELECT  commodity,  COUNT(commodity) `count` 
FROM    orders 
GROUP   BY commodity
HAVING  COUNT(commodity) =
(
    SELECT MAX(`COUNT`) 
    FROM
    (
        SELECT  COUNT(commodity) `count` 
        FROM    orders 
        GROUP   BY commodity
    )   s
)

Answer 2

試試這個查詢

  SELECT commodity,COUNT(commodity) AS count 
    FROM orders
GROUP BY commodity
ORDER BY count desc
   LIMIT 1;

Answer 3

我會寫：

select * from (SELECT commodity, COUNT(commodity) count FROM orders GROUP BY commodity ORDER BY count desc) where rownum <2;

Answer 4

只需添加desc即可

SELECT commodity, COUNT(commodity) count FROM orders GROUP BY commodity ORDER BY count DESC;

第一行將具有最大值並添加限制以獲得這一條記錄

SELECT commodity, COUNT(commodity) count FROM orders GROUP BY commodity ORDER BY count DESC LIMIT 1;

Answer 5

看起來你做得對。 除了ORDER BY以ASC順序命令它們。 讓它下降

mysql> SELECT commodity, COUNT(commodity) count FROM orders GROUP BY commodity ORDER BY count DESC;