計數SQL

Question

我有一個表稱爲[查看結果]，看起來有點像下面這樣：

[Reviewed By]....[Review Date]....[Corrective Action]....[CAR] 
John.............1/1/2011.........yes....................yes 
John.............2/5/2011.........No.....................yes 
John.............2/24/2011........yes....................yes 
Bobby............1/1/2011.........No.....................No 
Bobby............3/1/2011.........yes....................No 

我試圖通過評審在指定時間內顯示的[Corrective Action] = yes數量，也[CAR] = yes由評論者在指定時期內的數量。我嘗試使用以下的SQL，但它沒有給出正確的輸出：

select 
[Reviewed By], 
Count(IIF([Corrective Action] = yes, 1,0)) as [CAMBRs], 
Count(IIF([CAR] = yes,1,0)) as [CARs] 

from [Review Results] 

where [Review Date] between #1/1/2011# and #3/1/2011# 

group by 
[Reviewed By] 

有人可以用SQL指向正確的方向嗎？

Answer 1

select 
[Reviewed By], 
SUM(IIF([Corrective Action] = "yes", 1,0)) as [CAMBRs], 
SUM(IIF([CAR] = "yes",1,0)) as [CARs] 

from [Review Results] 

where [Review Date] between #1/1/2012# and #3/1/2012# 

group by 
[Reviewed By] 

Answer 2

也許是這樣的：

select 
    [Reviewed By], 
    SUM(IIF([Corrective Action] = True, 1,0)) as [CAMBRs], 
    SUM(IIF([CAR] = True,1,0)) as [CARs] 

from [Review Results] 

where [Review Date] between #1/1/2012# and #3/1/2012# 

group by 
[Reviewed By]