DataTable dataTable = GetDataTable();
 
                var importdata = from row in dataTable.AsEnumerable()
                            select new ImportRow()
                            {
                                GroupExtID = row.Field(SubjectsImportStructure.PID),
                                ExtID = row.Field(SubjectsImportStructure.ID),
                                Condition = row.Field(SubjectsImportStructure.Condition),
                                IC = row.Field(SubjectsImportStructure.IC),
                                RC = row.Field(SubjectsImportStructure.RC),
                            };
 
            IQueryable data = importdata as IQueryable;