import 3 digit field with leading zero

Question

ASP.NET, C#, MVC 3, Code First project

I'm trying to import data from an Excel spreadsheet. I've formated all cells as Text.
A sample row in the Import worksheet is as follows.

Account             Card               ThreeCode  Route  
04562954830287127   32849321890233127  183        154839254 
04562954830287128   32849321890233128  233
04562954830287129   32849321890233129  082
04562954830287130   32849321890233130  428

When I run in debug and drill down into the ds DataSet the Account and Card columns are imported as strings, the 3-Digit and Route columns are imported as doubles. The problem arises with the 3 digit number starting with 0 (082) in data row 3. It gets imported as a System.DBNull and is empty. I need to be able to import 3 digit codes with leading zeros. Is there a way to force the import to be all strings or another way to approach this problem? I searched the web for and haven't found a solution. This will run from a browser so anything to do with the registry, dll or ini files on the local machine is not an option. The import code is below. Thank you in advance for any help.

public ActionResult ExcelToDS(string Path = "C;\File.xls")
{ 
  string strConn = "Provider= Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Path + "; " + "Extended Properties=Excel 8.0;";

  OleDbConnection conn = new OleDbConnection(strConn);
  conn.Open(); string strExcel = "";
  OleDbDataAdapter myCommand = null;
  DataTable dt = new DataTable();
  strExcel = "select * from [Import$]";
  DataSet ds = null; 
  myCommand = new OleDbDataAdapter(strExcel, strConn);
  ds = new DataSet(); myCommand.Fill(ds, "table1");

Answer 1

There doesn't appear to be a way to make this work consistently. The work around I came up with is to add 1000 to the ThreeCode column in the Excel workbook. You are then able to import the data into a dataset. Then when the data is read out you simply strip off the "1" preifx. Here is my inline method to do that.

public static string last3(this string instring)
{ int len = instring.Length - 3; string outstring = instring.Substring(len, 3); return outstring; }

Which you can call in the code with:

card.3Dig = code.last3();

'card' and '3dig' are the class and field being populated. 'code' is the 4 digit dataset data.

Answer 2

Ah yes the joys of the excel driver. What happens is it makes a determination from the first say ten rows on the data type, anything outside of that format becomes null.

Solutions are to use a more robust third party driver usually costing something, or set the registry key to fully sample all of the rows rather than the default 8.

Check out the link here for TypeGuessRows http://www.connectionstrings.com/excel

HKLM\Software\Wow5432Node\Microsoft\Jet\4.0\Engines\Excel Set the value TypeGuessRows equal to zero