当在DataSet中绑定检索到的excel列时，除最后一列外，所有列都被检索绑定

我需要在ASP中导入excel文件。净MVC。导入工作按需进行，excel文件中有78列。除最后一列外，所有列都被导入。

我怎么能从excel文件检索最后一列?

string conString = string.Empty;
                        if (getFileExtension.ToLower() == ".xls")
                        {
                            conString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + getFileName + ";Extended Properties='"Excel 8.0;HDR=Yes;IMEX=2'""; ;
                        }
                        else if (getFileExtension.ToLower() == ".xlsx")
                        {
                            conString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + getFileName + ";Extended Properties='"Excel 12.0;HDR=Yes;IMEX=2'"";
                        }
                        OleDbConnection con = new OleDbConnection(conString);
                        if (con.State == ConnectionState.Closed) con.Open();
                        DataTable ExcelSheets = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
                        string SpreadSheetName = ExcelSheets.Rows[0]["TABLE_NAME"].ToString();
                        string query = "SELECT * FROM [" + SpreadSheetName + "]";
                        OleDbCommand cmd = new OleDbCommand(query, con);
                        OleDbDataAdapter da = new OleDbDataAdapter(cmd);
                        DataSet ds = new DataSet();
                        da.Fill(ds);
                        da.Dispose();
                        con.Close();
                        con.Dispose();