试图设置会话变量

Question

if(isset($_SESSION['admin'])) {
echo "<li><b>Admin</b></li>";
}

<?php
session_name('MYSESSION');
session_set_cookie_params(0, '/~cgreenheld/');
session_start();

$conn = blah blah
$query2 = 'Select Type from User WHERE Username = "'.$_SESSION['user'].'" AND Type =\'Admin\'';
$result2 = $conn->query($query2);
if($result2->num_rows==1) {
$_SESSION['admin'] = $result2;
}
?>

Hi, I'm trying to set this session variable but it doesn't seem to be setting, and i'm wondering if anyone can help. If session['admin'] isset it should echo the admin button. But i'm not quite sure why? (I do have session start and everything on everypage, it's not a problem with that or any of the "You don't have php tags" I have checked the mysql query, and it does return something from my table. Any ideas please?

Answer 1

Your session_start(); should be at the top of the page before anything to do with the session variables.

From the docs :

When session_start() is called or when a session auto starts, PHP will call the open and read session save handlers.

Edit from comments:

<?php
    session_name('MYSESSION');
    session_set_cookie_params(0, '/~cgreenheld/');
    session_start();
    // Moved to start after answer was accepted for better readability
    // You had the <?php after this if statement? Was that by mistake?
    if(isset($_SESSION['admin'])) 
    {
        echo "<li><b>Admin</b></li>";
    }

    // If you have already started the session in a file above, why do it again here?

    $conn = blah blah;
    $query2 = 'Select Type from User WHERE Username = "'.$_SESSION['user'].'" AND Type =\'Admin\'';
    // Could you echo out the above statement for me, just to 
    // make sure there aren't any problems with your sessions at this point?
    $result2 = $conn->query($query2);
    if($result2->num_rows==1) 
    {
        $_SESSION['admin'] = $result2;
        // It seems you are trying to assign the database connection object to it here.
        // perhaps try simply doing this:
        $_SESSION['admin'] = true;
    }
?>

Edit 2 from further comments:

You have to actually fetch the fetch the data like this - snipped from this tutorial which might help you out some more:

$query  = "SELECT name, subject, message FROM contact";
$result = mysql_query($query);

while($row = mysql_fetch_array($result, MYSQL_ASSOC))
{
    echo "Name :{$row['name']} <br>" .
     "Subject : {$row['subject']} <br>" .
     "Message : {$row['message']} <br><br>";
} 

But having said that, while we are talking about it, you would be better off moving away from the old mysql_* functions and move to PDO which is much better.

Answer 2

Move session_start(); to the top of the page. You are trying to retrieve sessions, where it's not loaded.

EDIT: Try echoing $_SESSION['admin'] , if it even contains something. Also try debugging your if($result2->num_rows==1) code by adding echo('its working'); or die('its working'); inside it, to check if $result2 contains exactly 1 row, since currently it seems $result2 contains either more than 1 row or no rows at all.