按指定返回所有捐赠者的最高SUM值

Question

我有以下脚本：

SELECT DISTINCT GIFT_ID, GIFT_DESG, SUM(GIFT_AMT)
FROM GIFT_TABLE
GROUP BY GIFT_ID, GIFT_DESG

它将返回如下内容：

GIFT_ID         GIFT_DESG      SUM(GIFT_AMT)
      1                A               25
      1                B              500
      1                C               75
      2                A              100
      2                B              200
      2                C              300
      ...

我期望的结果是：

GIFT_ID         GIFT_DESG      SUM(GIFT_AMT)
      1                B           500
      2                C           300

我该怎么办？

可能是row_number（）对吗？我认为通过指定的礼物金额的总和会让我失望。

谢谢。

Answer 1

如果您的DBMS支持ROW_NUMBER窗口函数，您可以尝试通过GIFT_ID按SUM(GIFT_AMT)顺序排序，然后获取rn = 1行。

SELECT t1.GIFT_ID,t1.GIFT_DESG,t1.GIFT_AMT 
FROM (
    SELECT t1.*,ROW_NUMBER() OVER(PARTITION BY GIFT_ID ORDER BY GIFT_AMT DESC) rn
    FROM (
      SELECT  GIFT_ID, GIFT_DESG, SUM(GIFT_AMT) GIFT_AMT
      FROM GIFT_TABLE
      GROUP BY GIFT_ID, GIFT_DESG
    ) t1
) t1
where rn =1

注意

您已经使用GROUP BY DISTINCT关键字是没有意义的，您可以从查询中删除它。

---

这是一个例子

CREATE TABLE T(
   GIFT_ID int,
   GIFT_DESG varchar(5),
  GIFT_AMT int
);


insert into t values (1,'A' ,25);
insert into t values (1,'B' ,500);
insert into t values (1,'C' ,75);
insert into t values (2,'A' ,100);
insert into t values (2,'B' ,200);
insert into t values (2,'C' ,300);

查询1：

SELECT t1.GIFT_ID,t1.GIFT_DESG,t1.GIFT_AMT 
FROM (
    SELECT t1.*,ROW_NUMBER() OVER(PARTITION BY GIFT_ID ORDER BY GIFT_AMT DESC) rn
    FROM T t1
) t1
where rn =1

Results：

| GIFT_ID | GIFT_DESG | GIFT_AMT |
|---------|-----------|----------|
|       1 |         B |      500 |
|       2 |         C |      300 |

Answer 2

您可以在没有子查询的情况下执行此操作：

SELECT TOP (1) WITH TIES GIFT_ID, GIFT_DESG, SUM(GIFT_AMT)
FROM GIFT_TABLE
GROUP BY GIFT_ID, GIFT_DESG
ORDER BY ROW_NUMBER() OVER (PARTITION BY GIFT_ID ORDER BY SUM(GIFT_AMT) DESC);

Answer 3

你也可以这样做

WITH t as
   SELECT GIFT_ID, GIFT_DESG, SUM(GIFT_AMT) AS GIFT_AMT
   FROM GIFT_TABLE
   GROUP BY GIFT_ID, GIFT_DESG)
SELECT  GIFT_ID, 
   max(GIFT_DESG) KEEP (DENSE_RANK LAST ORDER BY GIFT_AMT), 
   max(GIFT_AMT) GIFT_AMT
FROM T
GROUP BY GIFT_ID;