Question

我正在创建一个缓慢变化的维度表，以便记录某人何时更改了计划以及他们将其更改为

的内容

这要求我存储星期几，其中包含与之关联的开始时间和结束时间，信息位于以UserID，星期几，StartTime，EndTime结构的表中，然后每天都有一行值。每个用户的一周。

最好的方法是将其展平并将其存储到一个表格中，以便我可以检索一周中任何一天的“开始”停止时间。我正在考虑一周中每一天的列，包括开始时间和停止时间。例如Monday_Start，Monday_End。一周中这一天的特定日期与此无关，因为rowstartdate列和rowenddate列记录了该方面。

Answer 1

我认为没有理由在这里借助当前指示字段来使用数据库视图。

假设你有一个Type 2 Dimension：

 UserID
,DayOfWeek
,StartWorkTime
,EndWorkTime
,EffectiveStartDate
,EffectiveEndDate
,Current -- Y/N Flags for being current or not current

您可以有效地创建一个数据库视图，将StartWorkTime和EndWorkTime转换为UserID和Current列。

 CREATE VIEW [schema].[view_name] AS
 SELECT
    UserID
   ,[Current] -- Y = Yes / N = No
   ,MAX(CASE WHEN DayOfWeek = 2 THEN StartWorkTime  ELSE NULL END) AS Mon_StartWorkTime
   ,MAX(CASE WHEN DayOfWeek = 2 THEN EndWorkTime    ELSE NULL END) AS Mon_EndWorkTime 
   ,MAX(CASE WHEN DayOfWeek = 3 THEN StartWorkTime  ELSE NULL END) AS Tue_StartWorkTime
   ,MAX(CASE WHEN DayOfWeek = 3 THEN EndWorkTime    ELSE NULL END) AS Tue_EndWorkTime 
   ,MAX(CASE WHEN DayOfWeek = 4 THEN StartWorkTime  ELSE NULL END) AS Wed_StartWorkTime
   ,MAX(CASE WHEN DayOfWeek = 4 THEN EndWorkTime    ELSE NULL END) AS Wed_EndWorkTime 
   ,MAX(CASE WHEN DayOfWeek = 5 THEN StartWorkTime  ELSE NULL END) AS Thu_StartWorkTime
   ,MAX(CASE WHEN DayOfWeek = 5 THEN EndWorkTime    ELSE NULL END) AS Thu_EndWorkTime 
   ,MAX(CASE WHEN DayOfWeek = 6 THEN StartWorkTime  ELSE NULL END) AS Fri_StartWorkTime
   ,MAX(CASE WHEN DayOfWeek = 6 THEN EndWorkTime    ELSE NULL END) AS Fri_EndWorkTime 
 FROM [database].[schema].[table_name]
 WHERE [Current] = 'Y'
 GROUP BY
    UserID
   ,[Current]

那么您的结果将是一名员工在某天工作0800到1600，其他工作日为1200天

UserID  Current Mon_StartWorkTime   Mon_EndWorkTime     Tue_StartWorkTime   Tue_EndWorkTime     Wed_StartWorkTime   Wed_EndWorkTime     Thu_StartWorkTime   Thu_EndWorkTime     Fri_StartWorkTime   Fri_EndWorkTime
1       Y       08:00:00.0000000    16:00:00.0000000    08:00:00.0000000    16:00:00.0000000    08:00:00.0000000    16:00:00.0000000    08:00:00.0000000    12:00:00.0000000    08:00:00.0000000    12:00:00.0000000

使用Time Spans存储一周中几天的最佳方式

1 个答案: