sql - SQL 月基，每天只显示月基一次，左连接

Question

我已将“月基”添加到我的时间表中。现在我想将它添加到 Fact 表中。使用左连接：

 SELECT t1.[Posting_Date]
       ,t1.[Quantity]
       ,t1.[EmployeeID] --added afterwards
       ,t2.[Monthbase]
   FROM [Fact table] t1 LEFT JOIN [Time table] t2
     ON t1.[Posting_Date] = t2.[Posting_Date]

但如果适用，我只想每天一次查看值 (8)。已经创建了时间表，其中包含有关假期等的所有要求。

Answer 1

像这样的东西：

;WITH CTE AS
(
  SELECT [EmployeeID],
        [Posting_Date]
       ,[Quantity]
       ,ROW_NUMBER() OVER (PARTITION BY [EmployeeID], [Posting_Date] ORDER BY [Quantity]) RN
   FROM [Fact table]
)
SELECT t1.[Posting_Date]
       ,t1.[EmployeeID]
       ,t1.[Quantity]
       ,CASE WHEN t1.RN = 1 THEN t2.[Monthbase] ELSE 0 END [Monthbase]
   FROM CTE t1
     LEFT JOIN [Time table] t2
       ON t1.[Posting_Date] = t2.[Posting_Date]