尝试按顺序添加 DENSE_RANK() 的新列

Question

我希望一些例子可以帮助解释这种情况。

SELECT 
    ID,
    --ROW_NUMBER() OVER (PARTITION BY CardNumber ORDER BY ID DESC) AS 'RN',
    DENSE_RANK() OVER (ORDER BY CardNumber DESC) AS Rank,
    CardNumber,
    StampNumber,
    AuditDate,
FROM [dbo].[XXXX]
ORDER BY ID DESC, AuditDate DESC, StampNumber DESC

我已经阅读了 DENSE_RANK()，它最接近我正在寻找的内容，但不完全是。运行这段代码给了我

ID	Rank	CardNumber	StampNumber	AuditDate
46	1	3	20	2022-03-07 03:45:50.343
45	1	3	20	2022-03-07 03:45:50.343
44	2	2	40	2022-03-07 03:45:50.343
43	2	2	30	2022-03-07 03:45:50.343
42	2	2	20	2022-03-07 03:45:50.343
41	2	2	10	2022-03-07 03:45:50.343
40	3	1	40	2022-03-07 03:45:50.343
39	3	1	30	2022-03-07 03:45:50.343
38	3	1	20	2022-03-07 03:45:50.343
37	3	1	10	2022-03-07 03:45:50.343
36	1	3	40	2022-03-07 03:45:50.343
35	1	3	30	2022-03-07 03:45:50.343
34	1	3	20	2022-03-07 03:45:50.343
33	1	3	10	2022-03-07 03:45:50.343

我要找的结果是

ID	Rank	CardNumber	StampNumber	AuditDate
46	1	3	20	2022-03-07 03:45:50.343
45	1	3	20	2022-03-07 03:45:50.343
44	2	2	40	2022-03-07 03:45:50.343
43	2	2	30	2022-03-07 03:45:50.343
42	2	2	20	2022-03-07 03:45:50.343
41	2	2	10	2022-03-07 03:45:50.343
40	3	1	40	2022-03-07 03:45:50.343
39	3	1	30	2022-03-07 03:45:50.343
38	3	1	20	2022-03-07 03:45:50.343
37	3	1	10	2022-03-07 03:45:50.343
36	4	3	40	2022-03-07 03:45:50.343
35	4	3	30	2022-03-07 03:45:50.343
34	4	3	20	2022-03-07 03:45:50.343
33	4	3	10	2022-03-07 03:45:50.343

我希望密集排名仍然按 CardNumber 对排名进行分组，但需要排名列按顺序增长而不是重置。我只希望获得前 3 名。

Answer 1

这是一种 gaps-and-islands 问题。 您正在尝试获取每组相同的排名数字CardNumber 值（无间隙），按 ID DESC.

排序

您不能为此使用 DENSE_RANK 或 ROW_NUMBER，因为它们会将具有相同 CardNumber 值的所有行放在一起。

有多种解决方案。这是一个：

WITH PrevValues AS (
     SELECT *,
       IsNewCardNumber = CASE WHEN CardNumber = LAG(CardNumber) OVER (ORDER BY ID DESC)
                        THEN NULL ELSE 1 END
     FROM XXXX
)
SELECT
  ID,
  Rank = COUNT(IsNewCardNumber) OVER (ORDER BY ID DESC),
  CardNumber,
  StampNumber,
  AuditDate
FROM PrevValues;

db<>fiddle

尝试按顺序添加 DENSE_RANK() 的新列

Trying to add new column with DENSE_RANK() in sequentially

sql-server

dense-rank

gaps-and-islands