[Mono-dev] 32bit OdbcDataReader DataTable.Load() works OK, but 64bit throws NullReferenceException

JinJi dzindzinovic at yahoo.com
Mon Mar 16 10:12:35 UTC 2015

I am working with Monodevelop 4.0.1 that comes with the game engine Unity 5

My ODBC driver in 64bit Windows 7 is:
Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb) 14.00.7010.1000
ACEODBC.DLL date: 15.feb.2013

public DataTable ReadExcel(string fileName, string sheetName)
  // ODBCJT32.DLL works with Unity 4.6 32bit, but not with Unity 5 64bit:
  //string connectionString = "Driver={Microsoft Excel Driver (*.xls)};
DriverId=790; Dbq=" + fileName + ";";
  // ACEODBC.DLL works with Unity 5 64bit:
  string connectionString = "Driver={Microsoft Excel Driver (*.xls, *.xlsx,
*.xlsm, *.xlsb)}; DriverId=790; Dbq=" + fileName + ";";
  OdbcConnection connection = new OdbcConnection(connectionString);

  string commandText = "SELECT * FROM [" + sheetName + "$]";
  OdbcCommand command = new OdbcCommand(commandText, connection);

  OdbcDataReader dataReader = command.ExecuteReader();

  DataTable dataTable = new DataTable();
  dataTable.Load(dataReader); // works with ODBCJT32.DLL, but with
ACEODBC.DLL it throws NullReferenceException


  return dataTable;

The line: "dataTable.Load(dataReader);" throws this exception:

NullReferenceException: Object reference not set to an instance of an object
System.Data.Odbc.OdbcDataReader.GetColumnAttribute (Int32 column,
FieldIdentifier fieldId)
System.Data.Odbc.OdbcDataReader.GetSchemaTable ()

Any help would be appreciated!

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