Question

有没有人有一个如何连接3个表的例子，我有以下语句，但我得到了一个缺失的a（语法错误“操作符错误”）

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)

感谢

Answer 1

发现问题，因为它是一个访问数据库，第一个来自语句，INNER JOIN需要在括号中，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

如果删除WHERE子句，您的查询是否会执行？立即跳出来的唯一一件事就是你的日期不一定是OleDB提供商想要的格式。

我的猜测是，您需要将日期封装为“2009年1月1日”或类似内容。

Answer 3

您的加入看起来没问题，但我认为您的问题可能在于您将“TaskNumber”与“aFromDate”进行比较;数字和日期在SQL中是不同的类型，并且应该导致尝试比较它们的问题。

Ms-Access：加入3个表

3 个答案: