使用日期字段來匹配SQL查詢

Question

我有點問題圍繞着這個不斷變化的維度的邏輯。我想將以下兩張表聯繫起來。我需要根據ID和生效日期將成本期間事實表與成本維度相匹配。

正如您所看到的 - 如果月份和年份字段大於其關聯成本維度的生效日期，則應採用該值。一旦將新的生效日期輸入到維度中，它應該將該值用於大於所述日期的任何時間段。

編輯：我對缺乏細節表示歉意，但成本維度實際上會有一個唯一的索引值，並且匹配引用的變化字段爲資源，項目，成本。我試圖將您提供的查詢與我的字段進行匹配，但是我收到了錯誤的輸出。

FYI：命名約定的變化：EngagementId是標識，資源是ConsultantId，和項目是專案編號

我已經改變了下面的圖片，這裏是我的查詢

 ,_cte(HoursWorked, HoursBilled, Month, Year, EngagementId, ConsultantId, ConsultantName, ProjectId, ProjectName, ProjectRetainer, RoleId, Role, Rate, ConsultantRetainer, Salary, amount, EffectiveDate) 
    as 
    (
    select sum(t.Duration), 0, Month(t.StartDate), Year(t.StartDate), t.EngagementId, c.ConsultantId, c.ConsultantName, c.ProjectId, c.ProjectName, c.ProjectRetainer, c.RoleId, c.Role, c.Rate, c.ConsultantRetainer, 
c.Salary, 0, c.EffectiveDate 
     from timesheet t 
     left join Engagement c on t.EngagementId = c.EngagementId and Month(c.EffectiveDate) = Month(t.EndDate) and Year(c.EffectiveDate) = Year(t.EndDate) 
     group by Month(t.StartDate), Year(t.StartDate), t.EngagementId, c.ConsultantName, c.ConsultantId, c.ProjectId, c.ProjectName, c.ProjectRetainer, c.RoleId, c.Role, c.Rate, c.ConsultantRetainer, 
c.Salary, c.EffectiveDate 

    ) 
    select * from _cte where EffectiveDate is not null 
    union 
    select _cte.HoursWorked, _cte.HoursBilled, _cte.Month, _cte.Year, _cte.EngagementId, _cte.ConsultantId, _cte.ConsultantName, _cte.ProjectId, _Cte.ProjectName, _cte.ProjectRetainer, _cte.RoleId, _cte.Role, sub.Rate, _cte.ConsultantRetainer,_cte.Salary, _cte.amount, sub.EffectiveDate 
     from _cte 
     outer apply (
       select top 1 EffectiveDate, Rate 
       from Engagement e 
       where e.ConsultantId = _cte.ConsultantId and e.ProjectId = _cte.ProjectId and e.RoleId = _cte.RoleId 
       and Month(e.EffectiveDate) < _cte.Month and Year(e.EffectiveDate) < _cte.Year 
       order by EffectiveDate desc 
      ) sub 
    where _cte.EffectiveDate is null 

例子：

我正在努力編寫與此一致的查詢。起初，我試圖按最大日期進行分組。但是，當我執行加入時，我獲得了每個單一時期（甚至是生效日期之前的最高生效日期）的最高生效日期。

這是可以在查詢中完成的事情，還是我應該專注於目標表的增量更新，以便過去的任何有效日期/時間段都是獨立的？

任何提示將是偉大的！

感謝， 錢寧

Answer 1

試試這個：

; with _CTE as(
    select p.* , c.EffectiveDate, c.Cost 
    from period p 
     left join CostDimension c on p.id = c.id and p.Month = DATEPART(month, c.EffectiveDate) and p.year = DATEPART (year, EffectiveDate) 
) 
select * from _CTE Where EffectiveDate is not null 

Union 

select _CTE.id, _CTE.Month, _CTE.Year, sub.EffectiveDate, sub.Cost 
from _CTE 
    outer apply (select top 1 EffectiveDate, Cost 
        from CostDimension as cd 
        where cd.Id = _CTE.id and cd.EffectiveDate < DATETIMEFROMPARTS(_CTE.Year, _CTE.Month, 1, 0, 0, 0, 0) 
        order by EffectiveDate desc 
       ) sub 
where _Cte.EffectiveDate is null