Session variable not stored on other pages

Question

i am using session variable to send details of user from login page to welcome page .

here is my code :

<?php   

 if(isset($_POST['login']))
 {



 $email=$_POST['email'];
 $pass=md5($_POST['password']);


 $a="SELECT * FROM users WHERE email='$email'AND password='$pass'";
 $log=mysqli_query($con,$a);
$row=mysqli_fetch_array($log);


if(mysqli_num_rows($log)>0){

 $_SESSION['firstname']=$row['first_name'];
$_SESSION['lastname']=$row['last_name'];


header("location:welcome.php");
exit;
}
else{

$er="login failed!";

 }
}

on Welcome.php

 <h2>WELCOME : <?php echo $_SESSION['firstname'];?></h2>  <--- line 63-->

but i am getting this error :

Notice: Undefined index: firstname in C:\xampp\htdocs\website\welcome.php on line 63

PS : kindly dont mark it as duplicate I tried many solutions but not helping. I used session_start(); on every page .

Have you tried to put session_start() at the top in both files at the same time? — Sam Segers, Dec 15 '17 at 15:44
Check what session array prints on welcome.php page. print_r($_SESSION); — Ravinder Reddy, Dec 15 '17 at 15:45
no, I included the session_start(); in header.php and included it on all pages . — basiclearner, Dec 15 '17 at 15:46
Array ( [username] => basiclearner [session] => mc7dvh7u6n232dc23ipb6l4bok ) this is i am getting with print_r($_SESSION) on welcome .php basiclearner is the name i used but it keeps giving me the same name everywhere . — basiclearner, Dec 15 '17 at 15:48
I suggest you to check the session after setting firstname and lastname and before redirection. — Ravinder Reddy, Dec 15 '17 at 15:52
i echoed all the $_SESSION values giving perfect result on same page before redirecting to welcome.php . — basiclearner, Dec 15 '17 at 15:56
@basiclearner In your session variables the index was `username`, not `firstname`. — MCMXCII, Dec 15 '17 at 16:05
it was old session variable no variable is showing now . only session id — basiclearner, Dec 15 '17 at 16:10
I hope this post will help you. https://stackoverflow.com/questions/17242346/php-session-lost-after-redirect — Ravinder Reddy, Dec 15 '17 at 16:11
Really md5 password hashing in 2017? i advice you to read this http://php.net/manual/en/faq.passwords.php.. you also might want to read this https://stackoverflow.com/questions/60174/how-can-i-prevent-sql-injection-in-php to prevent SQL injections — Raymond Nijland, Dec 15 '17 at 16:33
i am in early stages of learning it is the basic thats why i am using md5 . — basiclearner, Dec 15 '17 at 16:48

jasinth premkumar · Answer 1 · 2017-12-15T16:44:09.970

1

A session is started with the session_start() function.

in 1st page:

if(mysqli_num_rows($log)>0){


    $row=mysqli_fetch_array($log);
    session_start();
    $_SESSION['firstname']=$row['first_name'];
    $_SESSION['lastname']=$row['last_name'];

    if(isset($_SESSION['firstname']))  
        header("location:welcome.php");
    exit;
}

on page 2:you might have write this line at 1st line:

<?PHP 
  session_start();
 ?>
 <h2>WELCOME : <?php if(isset($_SESSION['firstname']))  {echo $_SESSION['firstname'];}?></h2>

edited Dec 15 '17 at 16:44

answered Dec 15 '17 at 16:18

jasinth premkumar

1,430
1
12
22

OP sais: `I used session_start(); on every page .` – kscherrer Dec 15 '17 at 16:19
I used session_start(); on everypage . – basiclearner Dec 15 '17 at 16:28
@basiclearner also, please make sure that in your welcome.php page, there is no space or anything before the `` – kscherrer Dec 15 '17 at 16:31

kscherrer · Answer 2 · 2017-12-15T16:22:27.827

0

Edit: this answer is not correct and I will remove it when the comment-discussion has ended.

You fetch the first row of $log and then AFTER that check if the number of rows in $log is bigger than 0. Although you had one row initially, you fetched it! so at the time you check mysqli_num_rows($log) it will be 0, therefore never setting $_SESSION['firstname'] and $_SESSION['lastname'].

Try checking for number-of-entries before fetching the row like this:

$a="SELECT * FROM users WHERE email='$email'AND password='$pass'";
$log=mysqli_query($con,$a);

if(mysqli_num_rows($log)>0){


    $row=mysqli_fetch_array($log);

    $_SESSION['firstname']=$row['first_name'];
    $_SESSION['lastname']=$row['last_name'];


    header("location:welcome.php");
    exit;
}

edited Dec 15 '17 at 16:22

answered Dec 15 '17 at 16:11

kscherrer

5,486
2
19
59

If that is the case, redirection should also not work. – Ravinder Reddy Dec 15 '17 at 16:14
@basiclearner can you var_dump the `$row` and give us the result? – kscherrer Dec 15 '17 at 16:19

Session variable not stored on other pages

2 Answers2