session_start();

$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "somedatabase";

try {

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// prepare sql and bind parameters
$stmt = $conn->prepare("INSERT

                        INTO

                        patients

                            ( comments )

                        VALUES

                            ( :comment )

                        WHERE


                        unique_id = :unique_id

                             ");


$stmt->bindParam( ':comment',           $comment    );
$stmt->bindParam( ':unique_id',         $unique_id  );



 $comment          =   $_POST[      'comment'     ];
 $unique_id        =   $_SESSION[   'unique_id'        ];


$stmt->execute();





//header('Location: newMedicine.php');

}
catch(PDOException $e)
{
echo "Error: " . $e->getMessage();
}
$conn = null;

$comment          =   $_POST[      'comment'     ];
 $unique_id        =   $_SESSION[   'unique_id'        ];