Question

我在旧的XP机器上创建一个32位应用程序，这个应用程序也可以在Win7或更高版本上运行。

所以我试图测试连接字符串是否有效。如：

Private Function test_ace_or_jet(ByVal mdb_path As String) As String
        Dim connString As String
        Dim dbMaintPort As OleDb.OleDbConnection

        connString = ""

        Try
            connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & mdb_path

            dbMaintPort = New OleDb.OleDbConnection(connString)
            dbMaintPort.Open()

            dbMaintPort.Close()

            MsgBox("1 was found")
        Catch ex As Exception
            MsgBox("Could not open 1" & vbCrLf & vbCrLf & ex.Message)
            Try
                connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & mdb_path
                dbMaintPort = New OleDb.OleDbConnection(connString)
                dbMaintPort.Open()
                dbMaintPort.Close()

                MsgBox("2 was found")
            Catch ex2 As Exception
                connString = ""
                MsgBox("Could not open 2" & vbCrLf & vbCrLf & ex2.Message)
            End Try
        End Try
        test_ace_or_jet = connString
    End Function

然而，我发现的问题是在XP机器上，第一个连接字符串不会失败。它根本没有安装ACE。

如何测试是否使用其中一种？我能够得到上面的函数给我正确的连接字符串吗？

Answer 1

如果你继续做你的尝试/捕获，直到找到一些东西，你可能会非常深入地嵌套自己...你可能会更好（在测试时），做一个循环并且有一个类似于

Private Function test_ace_or_jet(ByVal mdb_path As String) As String
   Dim connString As String
   Dim dbMaintPort As OleDb.OleDbConnection
   Dim ValidConnection As Boolean
   Dim finalConnection As String
   Dim connStrings(2) As String
   connStrings(0) = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & mdb_path
   connStrings(1) = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & mdb_path
   connStrings(2) = "AnyOtherProviderTestConnectionStrings..."

   ValidConnection = False
   For value As Integer = 0 To 2
      Try
         dbMaintPort = New OleDb.OleDbConnection(connStrings(value))
         dbMaintPort.Open()
         dbMaintPort.Close()

         MsgBox("Success: " & connStrings(value))
         ValidConnection = True
         finalConnection = connStrings(value)
      Catch 
      End Try

      if ValidConnection
         exit
      endif 

   Next

   ; continue with whatever else you want to do with test result and final string

End Function

另外，你看过ConnectionStrings.com了吗？他们可能会为您提供更多选项和连接示例，以测试不同的提供商等。

找到正确的OleDb连接字符串VB.Net

1 个答案: