MS-訪問：加入3個表

Question

有誰有如何加入3個表，我有以下語句的例子，但我得到一個缺少（語法錯誤「操作錯誤」）

da = New OleDbDataAdapter("SELECT [S].[Scheduled Vege], [V].[Description], 
     [DS].[Task], [DS].[Task Date], [DS].[Completed] FROM [Scheduled] AS S 
     INNER JOIN [Date Schedules] AS DS ON [S].[SchedID] = [DS].[SchedID] 
     INNER JOIN [Vegetables Descriptions] AS V ON [V].[Task] = [DS].[Task] 
     WHERE [DS].[TaskNumber] >= " & aFromDate & " AND [DS].[TaskNumber] <= " & aToDate & " 
     AND [DS].[Completed] = '" & aCompleted & "' ", conn) 

謝謝

Answer 1

發現問題，因爲它是一個訪問數據庫，fisrt from語句和INNER JOIN需要在括號中，如下所示。

da = New OleDbDataAdapter("SELECT [S].[Scheduled Vege], [V].[Description], 
[DS].[Task], [DS].[Task Date], [DS].[Completed] FROM ([Scheduled] AS S 
INNER JOIN [Date Schedules] AS DS ON [S].[SchedID] = [DS].[SchedID]) 
INNER JOIN [Vegetables Descriptions] AS V ON [V].[Task] = [DS].[Task] 
WHERE [DS].[TaskNumber] >= " & aFromDate & " AND [DS].[TaskNumber] <= " & aToDate & " 
AND [DS].[Completed] = '" & aCompleted & "' ", conn) 

Answer 2

如果您刪除WHERE子句，是否執行查詢？立即跳出來的唯一的事情是你的日期不一定會成爲OleDB提供者喜歡的格式。

我的猜測是，你需要封裝你的日期，如'1-Jan-2009'或類似的東西。

Answer 3

您的加入看起來不錯，但我認爲您的問題可能是您將'TaskNumber'與'aFromDate'比較的位置;數字和日期在SQL中是不同的類型，並且會導致嘗試比較它們的問題。