Not Displaying Result

<?php
    $sql = <<<EOT SELECT COUNT(*) FROM tbl_session AS NUMBER
      WHERE session_date=CURDATE()
      AND session_status="Booked";
      EOT;
$result = $db->query($sql);

if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        echo "NUMBER". $row["NUMBER"]."<br>";
    }
} else {
    echo "0 results";
}
   ?>