Aggregate＆count「SELECT .... AS [Name]」field？

Question

我有這樣的SQL：

SELECT 
Mid(Note, 
    InStr(Note, "device.")- 
    (
    InStr(Note, "device.")- 
    InStr(Note, "pressure and") 
) 
    +13, 
    (InStr(Note, "device.") - InStr(Note, "pressure and")) - 14 
) 
    AS [Device], 
    Count([Device]), 
Date_Field & " " & Time_Field AS [DateTime], 
EnteredBy 
FROM MyLog 
WHERE Note LIKE "*removed and*" 
GROUP BY [Device] 
ORDER BY Date_Field DESC 
; 

我想GROUP BY是自定義字段[Device]和怎麼算每臺設備的許多有。但是上面的代碼給出了「... AS [Device]」部分的錯誤「...不包括指定的表達式......作爲聚合函數的一部分」。

我怎樣才能做到這一點？

現在的數據是這樣的：

Record1  12/05/12 03:02:12 User2 
Record1  12/02/12 01:02:12 User1 
Record1  12/01/12 02:02:12 User2 
Record2  12/06/12 03:02:12 User2 
Record2  12/07/12 03:02:12 User3 

但我想它看起來像：

Record1 3 
Record2 2 

這是舊的SQL工作（不聚合）：

SELECT Mid(Note, 
    InStr(Note, "device.")- 
    (
    InStr(Note, "device.")- 
    InStr(Note, "pressure and") 
) 
    +13, 
    (InStr(Note, "device.") - InStr(Note, "pressure and")) - 14 
) AS Device, Date_Field & " " & Time_Field AS [DateTime], EnteredBy 
FROM MyLog 
WHERE Note LIKE "*removed and*" 
ORDER BY Date_Field DESC; 

Answer 1

您不能在MS Access中的GROUP BY中引用別名設備，但可以創建子查詢並引用別名fr那個。

這將運行對我來說：

SELECT EnteredBy, Device, Count(Device) As CountDev FROM (
SELECT 
Mid(Note,InStr(Note,"device.")- 
     (InStr(Note,"device.")- 
      InStr(Note,"pressure and"))+13, 
    (InStr(Note,"device.")-InStr(Note,"pressure and"))-14) AS Device, 
MyLog.EnteredBy 
FROM MyLog 
WHERE MyLog.[Note] Like "*removed and*") 
GROUP BY EnteredBy, Device 

Answer 2

與此類似 - 基本上巢複雜的部分變成subbquery。

select dev, count(dev) from 
(
SELECT 
Mid(Note, 
    InStr(Note, "device.")- 
    (
    InStr(Note, "device.")- 
    InStr(Note, "pressure and") 
) 
    +13, 
    (InStr(Note, "device.") - InStr(Note, "pressure and")) - 14 
) 
    AS dev, 
Date_Field & " " & Time_Field AS DateTime, 
EnteredBy 
FROM MyLog 
WHERE Note LIKE "*removed and*" 
) 
GROUP BY dev 
ORDER BY DateTime DESC 

Answer 3

您正在收到該錯誤，因爲設備不是列。也許你可以使用子查詢，雖然我承認在一段時間內還沒有使用過Access。

嘗試這樣：

SELECT Count([Device]), Device, [DateTime], EnteredBy 
FROM (
SELECT 
Mid(Note, 
    InStr(Note, "device.")- 
    (
    InStr(Note, "device.")- 
    InStr(Note, "pressure and") 
) 
    +13, 
    (InStr(Note, "device.") - InStr(Note, "pressure and")) - 14 
) 
    AS [Device], 
    Date_Field & " " & Time_Field AS [DateTime], 
    EnteredBy 
FROM MyLog 
WHERE Note LIKE "*removed and*") t 
GROUP BY Device, [DateTime], EnteredBy 
ORDER BY Date_Field DESC 
; 

好運。