AJAX call sometimes stores the wrong value

[vikiesakki]

I have online examination portal, in which a user selects an answer and clicks next. At this point I make an AJAX call.

With each AJAX call I insert one row into the database. I'm storing marks as floats.

It should store either 1 or -0.25, but sometimes it stores 0, and I can't find the problem.

Here is my code:

Jquery Code:

var questin = $("#ques"+next).val(); var secin = $("#sect"+next).val();
$.ajax({
data:{ques:questin,answ:n,sec:secin},
method:'post',
async:false,
url:'result.php',
success:function(data){

}
});

PHP Code:

<?php
include("action/db.php");
session_start();
$ques_id = $_REQUEST['ques'];
$mark = (float) $_REQUEST['answ'];
$sec = $_REQUEST['sec'];
$exam_date_id = $_SESSION['ex_da'];
$use_id = $_SESSION['uid'];
$run->db_open();
$query2 = mysql_query("SELECT * FROM useranswers WHERE question_id='$ques_id' AND user_id='$use_id'");
$no = mysql_num_rows($query2);

if($no==0){
$date = date("Y:m:d:h:m:s");
$query1 = mysql_query("INSERT INTO useranswers VALUES ('','$exam_date_id','$use_id','$ques_id',0,'$sec','$mark','0','0','$date')");
}else{
$query1 = mysql_query("UPDATE useranswers SET mark='$mark' WHERE question_id='$ques_id'");
}
$run->db_close();
?>

[requinix]

That would mean the value of "n" from the Javascript would be 0 or something that cannot be converted to a number. Right?

 

So what is the actual value of n during those requests? Or alternatively, what does the AJAX request look like in terms of the form data submitted (which you should be able to get directly from the browser).

[vikiesakki]

1 or -0.25 is the actual value of 'n'. My problem is 5days its working normal but now its not working. i don't know what could be the problem.

[requinix]

So you're saying you tried making a bunch of requests, watching in the browser as each request gets sent, until you got one of them to insert 0 for a question? And the value of "n" in the browser (or the value of "answ" in the request data) is always 1 or -0.25?

 

Do you have email set up? Try something as simple as

if ($mark != 1 && $mark != -0.25) {
    mail("yourself@example.com", "mark={$mark}", var_dump($_REQUEST, true), "From: yoursendingaccount@example.com");
}

Then you'll get an email every time $mark doesn't have the right value, and it will include all the form data that was sent.

 

And you say it's a recent development? That must mean something has changed recently. Were there any changes to the site? Did your host upgrade PHP versions or change other configuration?