未找到数据源名称且未指定默认驱动程序

Question

I have been asked to port a WinForms app that uses the MVP pattern over to a webpage. The app, amongst other things, uploads a CSV file to a DataTable and then does some work.

The CSV file is uploaded to the server OK and then read with the following code

string connectionString = @"Driver={Microsoft Text Driver (*.txt; *.csv)};Extensions=asc,csv,tab,txt;Persist Security Info=False;Dbq=C:\Temp\";

//check that file exists and in correct format
if (File.Exists(this.WorkingFileName))
{                    
    using (OdbcConnection connection = new OdbcConnection(connectionString))
    {
        // Determine number of rows
        string selectCount = "select count(*) from [MyFile.csv]");

        using (OdbcCommand command = new OdbcCommand(selectCount, connection))
        {
            connection.Open();
        }
    }
}

at this point I get the error:

ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

Now the code works fine in WinForms but fails on the web. Is there something I need to change in IIS, my config file or something else to get this code to work? Or is there something more fundamental I need to do?

Update

OK so I worked out what was different between my two code versions: The WinForms version was running as 32-bit, as soon as I changed it to 64-bit it threw the same error. See: 32-bit Text drivers (Microsoft Access , Microsoft Excel and Text files ) from a 64 bit application on windows 7

To fix things I installed the Access 64-bit drivers from http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=13255 but I still get the same error.

If I check my ODBC Data Source Administrator I can see "Microsoft Access Text Driver (*.txt, *.csv) | 14.00.47600.1000 | Microsoft Corporation | ACEODBC.dll

So it looks like they're installed OK, so why would it still be failing?

Answer 1

OK, I found the problem. Just to summarise all the parts to my solution.

1. Uninstall any 32-bit Office apps (required for step 2)
2. Install the Access 64-bit drivers
3. Re-install any 32-bit Office apps

4. Change the connection string in TWO places as can be seen here to:

   @"Driver={Microsoft Access Text Driver (*.txt, *.csv)};Extensions=asc,csv,tab,txt;Persist Security Info=False;Dbq=C:\\Temp\\"

Note that:

1. The driver name has been changed to Microsoft Access Text Driver
2. The delimiter for the file extensions has been changed from a semi-colon to a comma .

I didn't spot the comma change which caused me a lot of pain :-(

Answer 2

This is probably due to the webserver not having the Jet Library installed, which I believe provides the Text Driver. It is probably installed locally due to coming with MS Office (again, I believe this is the case)

Answer 3

Is the connection string well formed? It seems that the dbq parameter is wrong.

"Driver={Microsoft Text Driver (*.txt; *.csv)};Extensions=asc,csv,tab,txt;Persist Security Info=False;Dbq=**C:Temp\\**"

Also take a look at this link , provides useful connection string samples