PHP Session Question

[Eos]

Hey Guys,

 

I'm relatively new to php and this is the first time i've tried to use php sessions. I'm attempting to create a semi e-commerce type page. Below is the code i'm using to set the session up, and, I believe I may have the wrong mentality about php session functionality.

 

if(!isset($_SESSION)) {
    if (session_start()) {
      mysql_query('INSERT INTO rooms ( created ) VALUES ( \''.date('Y-m-d H:i:s').'\' );');
      if ( $fr_room = mysql_fetch_assoc(mysql_query('SELECT roomid FROM rooms ORDER BY created DESC LIMIT 1;')) ) {
        $_SESSION['roomid'] = $fr_room['roomid'];
      }
      else {
        $_SESSION['roomid'] = -1;
      }
    }
  }

 

The mysql stuff in this example doesn't really matter, but my route of thinking is, the first thing this page does is check to see whether $_SESSION is set, effectively determining whether I session is active, if it isn't, start the session and set up some $_SESSION variables. But whenever I load the page, even if the session has already started, $_SESSION still isn't set and it goes ahead and inserts another value into the rooms table. (PS, roomid in this example is similar to a shopping cart id, so obviously I cant have it incrementing every time the page loads!)

 

Am I doing something wrong or, like I mentioned earlier, do I have the wrong mentality of how php sessions are supposed to work?

 

Any advice would be greatly appreciated, thanks.

[soycharliente]

You can just use session_start() as a stand alone.

 

session_start() creates a session or resumes the current one based on the current session id that's being passed via a request, such as GET, POST, or a cookie.

[Eos]

I see.

 

One moment i'll re-work it and re-post what i've got, let me know if i'm on the right track.

[dbo]

yeah just put session_start() at the very top of all your pages.

[soycharliente]

yeah just put session_start() at the very top of all your pages.

 

If you're going to do that, I would use an include or something. I usually have an include or require at the top of all my pages that includes a file that I can dump important things into that need to go on every single page.

[dbo]

If you have other stuff that is relevant that's not a bad idea. If not, it is, because:

 

session_start();

 

is easier to type than

 

include_once "someheaderfile.php";

 

and if all you had was session_start in this file then it would actually be slower doing the include.