我需要顯示零的字段的幫助

Question

在此查詢中，我計算了上週創建的工作訂單並顯示了wotype2的計數。如果前一週的wotype2爲零，我需要將wotype2顯示在我的結果中。關於如何解決這個問題的任何想法？

-- Retrieve Last Week's New Work Orders. 

DECLARE @TodayDayOfWeek INT 
DECLARE @EndOfPrevWeek DateTime 
DECLARE @StartOfPrevWeek DateTime 

--get number of a current day (1-Monday, 2-Tuesday... 7-Sunday) 
SET @TodayDayOfWeek = datepart(dw, GetDate()) 
--get the last day of the previous week (last Sunday) 
SET @EndOfPrevWeek = DATEADD(dd, -@TodayDayOfWeek, GetDate()) 
--get the first day of the previous week (the Monday before last) 
SET @StartOfPrevWeek = DATEADD(dd, -(@TodayDayOfWeek+6), GetDate()) 


SELECT wotype2 as WOType, COUNT(*) as NewWOsLastWeek 
FROM tasks 
WHERE ((OpenDATE BETWEEN 
    CONVERT(VARCHAR, @StartOfPrevWeek,7) AND 
    CONVERT(VARCHAR, @EndOfPrevWeek+1,7)) AND 
    (TYPE = 'Information Systems')  AND 
    (RESPONS != 'ADMIN')) 
group by wotype2 
order by wotype2 

Answer 1

您可能需要使用包含wotype2所有可能值的表進行外連接（如左外連接）。

如果有這樣一個表，假設它的命名wotype2s，那麼SQL將是：

SELECT wotype2s.wotype2 as WOType, COUNT(*) as NewWOsLastWeek 
FROM wotype2s left outer join tasks on wotype2s.wotype2 = tasks.wotype2 
WHERE ((OpenDATE BETWEEN 
    CONVERT(VARCHAR, @StartOfPrevWeek,7) AND 
    CONVERT(VARCHAR, @EndOfPrevWeek+1,7)) AND 
    (TYPE = 'Information Systems')  AND 
    (RESPONS != 'ADMIN')) 
group by wotype2s.wotype2 
order by wotype2s.wotype2 

，或者，如果沒有這樣的表，

SELECT wotype2s.wotype2 as WOType, COUNT(*) as NewWOsLastWeek 
FROM (select distinct wotype2 from tasks) wotype2s 
    left outer join tasks on wotype2s.wotype2 = tasks.wotype2 
WHERE ((OpenDATE BETWEEN 
    CONVERT(VARCHAR, @StartOfPrevWeek,7) AND 
    CONVERT(VARCHAR, @EndOfPrevWeek+1,7)) AND 
    (TYPE = 'Information Systems')  AND 
    (RESPONS != 'ADMIN')) 
group by wotype2s.wotype2 
order by wotype2s.wotype2