can a session be used in a query?

["Terion Miller" <webdev.terion@xxxxxxxxx>]

I am still struggling with getting my sessions and logins to pull just the
allotted data that each user is allowed...
I have the session working, and can echo it to see that .. what I'm having
problems with is this : I want to pull the data specific to each user
..right... so far I either get all data regardless of user privileges or I
get nothing.. a blank page, I have tried so many ways but never one that
works: here are a few I have worked with----

This one pulls all data regardless of user level:
<?php
error_reporting(E_ALL);
ini_set('display_errors', '1');
session_start();
include("inc/dbconn_open.php");


if (empty($_SESSION['AdminLogin']) OR $_SESSION['AdminLogin'] <> 'True' ){
    header ("Location: LogOut.php");
}


    $query =  "SELECT * FROM admin WHERE AdminID = AdminID";
    $result = mysql_query ($query);
    $row = mysql_fetch_object ($result);
?>

>From there I tried:

<?php
error_reporting(E_ALL);
ini_set('display_errors', '1');
session_start();
include("inc/dbconn_open.php");


if (empty($_SESSION['AdminLogin']) || $_SESSION['AdminLogin'] !=  true){
    header ("Location: LogOut.php");
}


    $query =
"SELECT * FROM `admin` WHERE `UserName` = `{$_SESSION['user']}";
    $result = mysql_query ($query);
    $row = mysql_fetch_assoc($result);
?>

this one didn't work with the if $row -> statements that are used to select
what menu items to load.

Now I have this one which loads nothing, nil a blank page:

 $query =  "SELECT * FROM  admin  WHERE  UserName  = "$_SESSION['user']" ";
    $result=mysql_query($query) or die('Queryproblem: ' . mysql_error() .
'<br />Executed            query: ' . $query);
             if (mysql_num_rows($result) >= '1'){
            while ($row = mysql_fetch_assoc($result)){
            echo $row['AddEditAdmin']; //to print out the value of column
'var1' for each record
      }
  }else{
                 echo 'No records found.';
   }
?>

anyone have ideas for me, the session user is working, and I need to use it
in the query to pull only that users data I also on the login page where I
set that session all set it to = $UserName but when I try and use that in
the query UserName = $UserName I get an undefined variable error...

Really trying but not quite getting it...