PHPExcel生成一些随机字符？

Question

I have the task of generating the excel sheet of each and every student separately so I used PHPExcel lib to perform the task

<?php
    $host='localhost'; $user='root'; $pass=''; $DataBase='college';//define the correct values
    // open the connexion to the databases server
    $Link=@mysqli_connect($host,$user,$pass,$DataBase) or die('Can\'t connect !');
    mysqli_set_charset($Link, 'utf8');//if not by default
    //your request
    if(isset($_GET['stud_id'])){
        $id=$_GET['stud_id'];

        $SQL='SELECT * from stud_master where stud_id=$id';
        $rs=mysqli_query($Link, $SQL);//get the result (ressource)
        /** Include PHPExcel */
        require_once 'ec/Classes/PHPExcel.php';//change if necessary

        // Create new PHPExcel object
        $objPHPExcel = new PHPExcel();
        $F=$objPHPExcel->getActiveSheet();
        $Line=1;
        while($Trs=mysqli_fetch_assoc($rs)){//extract each record
            $F->
                setCellValue('A'.$Line, $Trs['stud_id'])->
                setCellValue('B'.$Line, $Trs['course_id'])->
                setCellValue('C'.$Line, $Trs['fname'])->
                setCellValue('D'.$Line, $Trs['mname'])->
                setCellValue('E'.$Line, $Trs['lname']);//write in the sheet
            ++$Line;
        }
    }
    // Redirect output to a client’s web browser (Excel5)
    header('Content-Type: application/vnd.ms-excel');
    header('Content-Disposition: attachment;filename="report.xls"');
    header('Cache-Control: max-age=0');

    $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
    $objWriter->save('php://output');
    exit;

Answer 1

Seems, the you have an error in your SQL syntax:

//use double quotes here, not single - otherwise $id won't be substituted
$SQL = "SELECT * from stud_master where stud_id=$id";
$rs=mysqli_query($Link, $SQL);//get the result (ressource)

But better use prepared statements to protect from SQL injection.