PHP MYSQL Custom User Access Levels

PHP / MYSQL Simple User Access Levels

session_start();
//echo $_SESSION['username'];
$myuser = $_SESSION['username'];

if ($myuser) {
$command="SELECT * from users WHERE username='$myuser';";
$result = mysqli_query($db, $command);
if ($result && mysqli_num_rows($result) > 0){
while($row = mysqli_fetch_assoc($result)) {

if ($row['access_level']=='1') {

echo "Add stuff here!";

}

else if ($row['access_level']==0){
echo "Add specific stuff here!";
}
}
}
} else {
echo "Add general stuff here for any non-member!";
}