SQL Server：將行轉換爲一行

Question

我知道SQL Server Pivot，但是這次我想我需要更復雜的東西，然後是一個簡單的pivoted值。

Here it is an SQL fiddle example.

所以我有一個表，我有最多3行一種startcity - endcity組合。

在查詢中，我需要在一行中獲得這些組合，而我只需要那些組合，其中有3行。

請指教，

Answer 1

您可以像這樣做一個交叉表。

with NumberedValues as 
(
    SELECT EndCity 
     , StartDate 
     , EndDate 
     , Price 
     , ROW_NUMBER() OVER(PARTITION BY StartCity, EndCIty ORDER BY StartDate) as RowNum 
    FROM [dbo].[BestPrice] 
) 
SELECT EndCity, 
    max(CASE WHEN RowNum = 1 THEN StartDate END) as StartDate1, 
    max(CASE WHEN RowNum = 1 THEN Enddate END) as EndDate1, 
    max(CASE WHEN RowNum = 1 THEN Price END) as Price1, 
    max(CASE WHEN RowNum = 2 THEN StartDate END) as StartDate2, 
    max(CASE WHEN RowNum = 2 THEN Enddate END) as EndDate2, 
    max(CASE WHEN RowNum = 2 THEN Price END) as Price2, 
    max(CASE WHEN RowNum = 3 THEN StartDate END) as StartDate3, 
    max(CASE WHEN RowNum = 3 THEN Enddate END) as EndDate3, 
    max(CASE WHEN RowNum = 3 THEN Price END) as Price3 
FROM NumberedValues 
group by EndCity