无法从数据库表创建Excel文件

Question

这是我创建excel文件的PHP代码。即使excel正在创建，但数据不会从数据库表返回。

<?php


        $dbhost = "localhost"; 
        $dbuser = "MY DATABASE USERNAME"; 
        $dbpass = "MY DATABASE PASSWORD"; 

        function dbConnect($db="") {    global $dbhost, $dbuser, $dbpass; 

        $dbcnx = @mysql_connect($dbhost, $dbuser, $dbpass) 
                or die("The site database appears to be down."); 

        if ($db!="" and !@mysql_select_db($db)) 
            die("The site database is unavailable."); 
                    return $dbcnx; 
        } 


        require_once 'excel_files/Spreadsheet/Excel/Writer.php';

        $workbook = new Spreadsheet_Excel_Writer();
        $format_bold =& $workbook->addFormat();
        $format_bold->setBold();

        $worksheet =& $workbook->addWorksheet();
        $worksheet->write(0, 0, "Sl.No", $format_bold);
        $worksheet->write(0, 1, "Employee's Name", $format_bold);
        $worksheet->write(0, 2, "Net pay for the month", $format_bold);
        $worksheet->write(0, 3, "Account Number", $format_bold);
        //$worksheet->write(0, 4, "comments", $format_bold);

        # start by opening a query string
        $fullquery="select * from payroll";

        $result=mysql_db_query($dbuser,$fullquery);

        $i=1;
        while($row=mysql_fetch_assoc($result)){
                $worksheet->write($i, 0, "$row[sl_no]");
                $worksheet->write($i, 1, "$row[employee_name]");
                $worksheet->write($i, 2, "$row[salary]");
                $worksheet->write($i, 3, "$row[account_no]");
                //$worksheet->write($i, 4, "$row[comments]");
                $i++;
        }
        $workbook->send('test.xls');
        $workbook->close();
?>