在每5行中選擇最大值

我的總行數是可變的，並且不是固定的，所以有N行，我想將每5行分成一組，並在SQL中的下表中選擇價格的最大值。在每5行中選擇最大值

Date  Price 
20170101 100 
20170102 110 
20170103 90 
20170105 80 
20170109 76 

20170110 50 
20170111 55 
20170113 80 
20170115 100 
20170120 99 

20170121 88 
20170122 98 
2017

所以在第一組5最高價格是110，而第二組是100，而最後一組最高價格是120

來源

2017-08-14 MahdiIBM

使用公用表表達式對它們進行分組。

WITH CTE AS (SELECT RANK() OVER (ORDER BY Date) AS Rank, Price 
      FROM yourtable) 
SELECT (Rank - 1)/5 AS GroupedDate, MAX(Price) AS MAXPRICE 
FROM CTE 
GROUP BY ((Rank - 1)/5);

輸出

GroupedDate MAXPRICE 
0   110 
1   100 
2   120

SQL小提琴：http://sqlfiddle.com/#!6/b5857/3/0

來源

2017-08-14 14:29:21 Matt

工作就像一個魅力，讓我知道是有可能有日期選定的價格還？ – MahdiIBM

像在類似：'20170101 - 20170109 110' – Matt

不喜歡 - > 20170102 = 110 – MahdiIBM

你可以使用：

SELECT grp, MAX(Price) AS price 
FROM (SELECT *, ROW_NUMBER() OVER(ORDER BY DATE)/5 AS grp FROM tab) sub 
GROUP BY grp; 

-- OUTPUT 
grp price 
0 110 
1 100 
2 120

Rextester Demo

*假設日期是唯一的

編輯：

如像：20170101 - 20170109 110

SELECT 
    CONVERT(VARCHAR(8),MIN(DATE),112) + '-' + CONVERT(VARCHAR(8),MAX(date),112) 
    , MAX(Price) AS price 
FROM (SELECT *, (ROW_NUMBER() OVER(ORDER BY DATE))/5 AS grp FROM tab) sub 
GROUP BY grp;

輸出：

20170101-20170105 110 
20170109-20170115 100 
20170120-2017

Rextester Demo2

來源

2017-08-14 14:27:57 lad2025

您可以使用ROW_NUMBER如下

;With cte as (
Select *, Bucket = Sum(RowN) over(Order by [date]) from (
    Select *, RowN = case when row_number() over(order by [date]) % 5 = 0 then 1 else 0 end from #data1 
) a 
) Select top (1) with ties [Date], [Price] 
from cte 
order by row_number() over (partition by Bucket order by Price desc)

來源

2017-08-14 14:36:56

在每5行中選擇最大值

回答

相關問題