SQL 在另一列中具有最高值的名称值

Question

假设我有一个 table 像这样：

Store    | Item   | Price  
store01  | Apple  | 2.50  
store01  | Pear   | 3.00
store01  | Banana | 3.11  
store02  | Apple  | 2.50  
store02  | Pear   | 2.00
store03  | Banana | 3.10

我只想要一个列出所有商店并命名该商店中最昂贵商品的查询。所以我需要这样的东西：

Store   | Item  
store01 | Banana 
store02 | Apple 
store03 | Banana

我试过这样的事情：

SELECT "Store",
       (case when (max ("Price") = "Price") then "Item" end) as  "Max price Item"   
FROM Table 
group by "Price","Item","Store";

但结果只是：

Store   | Max price Item 
store01 | Apple 
store01 | Pear
store01 | Banana
store02 | Apple
store02 | Pear
store03 | Banana

我在 dashDB 运行。

Answer 1

你应该使用这个

SELECT t.Store,
    t.Item
FROM Table t
INNER JOIN
    (SELECT
        Store,
        MAX(Price) AS max_price
    FROM
        Table 
    GROUP BY 
        Store
    ) mt
ON 
    mt.Store = t.Store
    AND mt.max_price = t.Price;

或者其他方式可以是：

SELECT t.Store,
    t.Item
FROM Table t
WHERE (Store, Price) IN
    (SELECT
        Store,
        MAX(Price) AS max_price
    FROM
        Table 
    GROUP BY 
        Store
    );

Answer 2

尝试使用以下查询

SELECT Store,Item
  FROM YourTable T,
        (SELECT Store,max(Price) MPrice
         FROM YourTable
          GROUP BY Store
         ) AS T1
  WHERE T1.Store=T2.Store AND T1.Price=T2.MPrice

Answer 3

以下应该可以解决问题：

 SELECT Store, MAX(Price) FROM Table
 GROUP BY Store

或者

 SELECT
  b.Store,
  MAX(b.Price) as MaxPrice,
  MAX(b.Item) as Item
FROM Table b
INNER JOIN (SELECT 
              Store,
              MAX(Price) as MaxPrice
            FROM Table
            GROUP BY Store) a ON 
a.Store = b.Store AND a.MaxPrice = b.Price
GROUP BY b.Store

示例输入和输出：

SQL 在另一列中具有最高值的名称值

SQL name value with highest value in another column

sql

greatest-n-per-group

dashdb