Question

这是MCQ考试代码。代码中的所有内容都在工作，因为$ p3 [8]我没有得到所需的输出。它也无法打印$ p3 [8]值。

<?php

session_start();
error_reporting(1);
include("connect.php");

extract($_POST);
extract($_GET);
extract($_SESSION);
$username = $_SESSION['student'];   

if(isset($testid))
{
    //$_SESSION[sid]=$subid;
    //echo 'sads';

    $_SESSION['tid']=$testid;
    header("location:test.php");
}
if(!isset($_SESSION['tid']))
{//echo 'qwerwq';
    header("location:home.php");
}
?>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">


        <title>Online Exam</title>
        <link href="quiz.css" rel="stylesheet" type="text/css">
    </head>

<body>
<?php
include("head.php");



$rs=mysqli_query($con, "select * from addmcq where test_id=$tid",$cn);

$r = mysqli_num_rows($rs);

if($r==0)
{
    //header("location:test2.php");
}   
if(!isset($_SESSION['qn']))
{
 $_SESSION['qn']=0;
 mysqli_query($con, "delete from mcq_user where sess_id='$username' and  test_id=$tid") or die(mysql_error());
 $_SESSION['trueans']=0;

}
else
{   
if($submit=='Next MCQ' && isset($ans))
{
  mysqli_data_seek($rs,$_SESSION['qn']);
    $row= mysqli_fetch_row($rs);
    mysqli_query($con, "delete from mcq_user where sess_id='$username', test_id=$tid and ques=$row[3]");
    echo "ww";  
    mysqli_query($con, "insert into mcq_user(sess_id, test_id, que, ans1,ans2,ans3,ans4,true_ans,your_ans) values ('$username', $tid,'$row[3]','$row[4]','$row[5]','$row[6]', '$row[7]','$row[8]','$ans')") or die(mysql_error());

    if($ans==$row[8])
    {
        $_SESSION['trueans']=$_SESSION['trueans']+1;
    }
    $_SESSION['qn']=$_SESSION['qn']+1;

}
else if($submit=='Next EA' && isset($ans))
{
    mysqli_data_seek($rs,$_SESSION['qn']);
    $row= mysqli_fetch_row($rs);
    mysqli_query($con, "delete from mcq_user where sess_id='$username', test_id=$tid and ques=$row[3]");        
    mysqli_query($con, "insert into mcq_user(sess_id, test_id, que, ans1,ans2,ans3,ans4,true_ans,your_ans) values ('$username', $tid,'$row[3]','$row[4]','$row[5]','$row[6]', '$row[7]','$row[8]','$ans')") or die(mysql_error());

    if($ans==$row[8])
    {
       $_SESSION['trueans']=$_SESSION['trueans']+1;
      // echo $_SESSION['trueans']; 
    }

    //echo "<h1 class=head1> Result</h1>";
    $_SESSION['qn']=$_SESSION['qn']+1;

    //$_SESSION['trueans'];
     header("location:test2.php");              
    //echo '<br />Start short answer type questions<a href="test2.php">click here</a>'; 

}
else if($submit=='Previous MCQ' && isset($ans))
{
    mysqli_data_seek($rs,$_SESSION['qn']);
    $row= mysqli_fetch_row($rs);    
    mysqli_query($con, "insert into mcq_user(sess_id, test_id, que, ans1,ans2,ans3,ans4,true_ans,your_ans) values ('$username', $tid,'$row[3]','$row[4]','$row[5]','$row[6]', '$row[7]','$row[8]','$ans')") or die(mysql_error());

    if($ans==$row[8])
    {
        $_SESSION['trueans']=$_SESSION['trueans']+1;
    }
    $_SESSION['qn']=$_SESSION['qn']-1;

}


}

主要问题从这里开始$ p2也没有打印值

$rs=mysqli_query($con, "select * from addmcq where test_id=$tid",$cn) or die(mysql_error());
$r = mysqli_num_rows($rs);

$p1= mysqli_query($con, "select * from mcq_user where test_id=$tid and sess_id=$username");
$p2 = mysqli_num_rows($p1);
//echo "qqqqq";
 echo $p2;
if($r==0)
{
    header("location:test2.php");
}   
if($_SESSION['qn']>mysqli_num_rows($rs)-1)
{
//unset($_SESSION[qn]);
//echo "<h1 class=head1>Some Error  Occured</h1>";
//session_destroy();
//echo "Please <a href=head.php> Start Again</a>";
exit;
}
mysqli_data_seek($rs,$_SESSION['qn']);
mysqli_data_seek($p1,$_SESSION['qn']);
echo $_SESSION['qn'];

$row= mysqli_fetch_row($rs);

$ p3初始化并显示它以进行检查。

$p3= mysqli_fetch_row($p1);
echo $p3[8];

//include("tt.html");
 echo "<form name=myfm method=post action=test.php>";
 echo "<table width=100%> <tr> <td width=30>&nbsp;<td> <table border=0>";
 $n=$_SESSION['qn']+1;
echo "<tr><td><span class=style2>Que ".  $n .": $row[3]</style>";
echo "<tr><td class=style8><input ";
if($p3[8]==1) echo "checked='checked'";
echo " type=radio name=ans value=1>$row[4]";
echo "<tr><td class=style8> <input ";
if($p3[8]==2) echo "checked='checked'";
echo" type=radio name=ans value=2>$row[5]";
echo "<tr><td class=style8><input ";
if($p3[8]==3) echo "checked='checked'";
echo" type=radio name=ans value=3>$row[6]";
echo "<tr><td class=style8><input ";
if($p3[8]==4) echo "checked='checked'";
echo" type=radio name=ans value=4>$row[7]";
if($n == 1)
echo "<tr><td><input type=submit name=submit value='Next MCQ'><td><tr></form>";
if($_SESSION['qn']<mysqli_num_rows($rs)-1 && $n > 1)
echo "<tr><td><input type=submit name=submit value='Previous MCQ'><input type=submit name=submit value='Next MCQ'><td><tr></form>";
if($_SESSION['qn']== mysqli_num_rows($rs)-1)
echo "<tr><td><input type=submit name=submit value='Previous MCQ'><input type=submit name=submit value='Next EA'><td><tr></form>";
echo "</table></table>";


?>

</body>
</html>

Answer 1

确保此查询

$p1= mysqli_query($con, "select * from mcq_user where test_id=$tid and sess_id=$username");

将返回包含至少8列的记录......

还有一件事

如果$username是一个字符串，那么你应该使用单引号

 $p1= mysqli_query($con, "select * from mcq_user where test_id=$tid and sess_id='$username'");

无法打印价值

1 个答案: