聚合顶部以外的行

Question

假设我们有以下水果 table:

Fruit   | Qty
-------------
Apple   | 2
Apple   | 5
Apple   | 2
Orange  | 3
Orange  | 4
Orange  | 0
Banana  | 2
Banana  | 5
Pear    | 2
Mango   | 1
Mango   | 0

如果我想获得前 3 个水果，我会创建这样的查询：

SELECT TOP 3 Fruit, SUM(Qty) AS Total
FROM Fruits
GROUP BY Fruit
ORDER BY Total DESC

将return:

Apple   | 9
Orange  | 7
Banana  | 7

但是，如果我想包括不在前 3 名的水果的总和，我将不得不使用 NOT IN 编写这样的代码来排除前 3 名水果：

SELECT 'OTHER' AS Fruit, SUM(Qty) AS Total
FROM Fruits
WHERE Fruit NOT IN (SELECT Fruit FROM (SELECT TOP 3 Fruit, SUM(Qty) AS Total FROM Fruits GROUP BY Fruit ORDER BY Total DESC) AS Test)

如果我想在单个查询中执行此操作，我想我可以使用 UNION 组合这两个查询。我已经有了 B 计划，但我想知道 SQL 是否有任何内置方法来聚合不属于可用于简化查询的最高值的行？

Answer 1

这是根据 sum(qty).

对行进行排名的一种方法

with totals as (SELECT Fruit, SUM(Qty) AS Total FROM Fruits GROUP BY Fruit)
, rownums as (select *, dense_rank() over(order by total desc) as rank from totals)
select 
case when rank > 3 then 'Other' else fruit end as fruit, total
from rownums

如果 other 行需要聚合，请在 total 列和 group by case 语句中再包含一个 sum。

Answer 2

您需要对总和进行排序，并为最终结果添加另一个 SUM：

with cte as
 (
   SELECT Fruit, SUM(Qty) AS Qty,
      ROW_NUMBER() OVER (ORDER BY SUM(Qty) DESC) AS rn
   FROM Fruits 
   GROUP BY Fruit
 )
select 
   case when rn > 3 then 'Other' else fruit end as fruit, 
   sum(Qty)
from cte
group by 
   case when rn > 3 then 'Other' else fruit end
order by MIN(rn)

见Fiddle

Answer 3

几乎！，很遗憾你不能把排名放在一边！！但你不能。所以你必须有一个嵌套的 select 然后是一个 where.

加上这种方法，您可以获得任何您想要的组，即 BETWEEN AND 3.. > 3 .. IN(1,3,6) 等

DECLARE @Fruits TABLE (Fruit NVARCHAR(32),Qty INT)
INSERT INTO @Fruits(Fruit,Qty)
VALUES
('Apple',2),
('Apple',5),
('Apple',2),
('Orange',3),
('Orange',4),
('Orange',0),
('Banana',2),
('Banana',5),
('Pear',2),
('Mango',1),
('Mango',0)

SELECT TOP 3 Fruit, SUM(Qty) AS Total
FROM @Fruits
GROUP BY Fruit
ORDER BY Total DESC

SELECT A.Fruit,A.Total FROM
(
    SELECT Fruit, SUM(Qty) AS Total,RANK() OVER (ORDER BY SUM(Qty) DESC,Fruit) AS GroupNumber
    FROM @Fruits
    GROUP BY Fruit
) AS A
WHERE GroupNumber > 3 --This bit lets you pick the groups!
ORDER BY Total DESC

聚合顶部以外的行

Aggregate rows outside the top

sql

sql-server

aggregate

sql-server-2014