[RESOLU]
Bonjour,

merci,
j'ai trouvé le problème est dans la 2eme vérification dans .php
j'ai modifié de cette façon: $tv = isset($_POST['tv']) ? $_POST['tv'] : NULL;

$(function(){	
	//bouton enregistrer			
	$('#btnsave').click(function(event){
		event.preventDefault();
		var roomno_r		= $('#roomno').val();
		var tv_r 			= ($('#tv')[0].checked == true) ? "Y" : "";
		var aircondition_r 	= ($('#aircondition')[0].checked == true) ? "Y" : "";
	
		alert("btnsave JS : " + roomno_r + ", " + tv_r + ", " + aircondition_r);	
		$.ajax({
				url		: "room.php",
				method	: "POST",
				Async	: false,
				data	:{
							buttonsave 	: 1 ,
							roomno	: roomno_r ,
							tv			: tv_r ,
							aircondition: aircondition_r
						  },
				success	:function(result)
				{
					console.log(result);
				}
		});
	});
});

<?php
	include_once("_public.php");
	include_once("sql/sql.php");
	include_once("modele/modele.php");

	$connexion 	= new connection();
	$dbconnect 	= $connexion->connect();
	$requeteSql = new requeteSql();
	
	//ajouter une chambre
	if(isset($_POST['buttonsave']))
	{
		$roomno 		= $_POST['roomno'];
		$tv				= !isset($_POST['tv']) ? "'" . $_POST['tv'] . "'" : NULL;
		$aircondition	= !isset($_POST['aircondition']) ? "'" . $_POST['aircondition'] . "'" : NULL;
		
		echo "PHP : ".$roomno.",".$tv.",".$aircondition."<br>";
		$findQuery 		= "SELECT * FROM rooms WHERE roomno = '".$roomno."'";
		
		$resultat = $requeteSql->getRows2($findQuery);
		if (sizeof($resultat) > 0){
			echo "Existe déjà";
		}
		else{
			//insert
			$roomsSql  	= new roomsSql();
			$rooms  	= new rooms();

			$rooms->setRoomno($roomno);
			$rooms->setTv($tv);
			$rooms->setAircondition($aircondition);
	
			$roomsSql->ajouter(serialize($rooms));			
		}
	}
?>
<script type="text/javascript" src="js/jquery-1.12.4.js"></script>
<script type="text/javascript" src="js/roomListener.js"></script>
<form>
	chambre        :<input type="text"     id="roomno"       name="roomno"        value=""/><br>
	tv             :<input type="checkbox" id="tv"           name="tv"            value="Y"/>
	air conditione :<input type="checkbox" id="aircondition" name="aircondition"  value="Y"/><br>
					<input type="button"   id="btnsave"      name="btnsave"       value="Ajouter"/>
</form>

Bonjour,
Excuser-moi si j’ai balancé ce bout de code c’est uniquement pour m'eclaircir l’erreur :
J’ai mis une [b]alert[/b] au niveau de la fonction .js qui m’affiche bien les valeurs des checkBox par contre après insertion dans la base c’est vide. Merci d'avance pour votre aide.

[b]roomListener.js[/b]
[php]$(function(){
//bouton enregistrer
$('#btnsave').click(function(event){
event.preventDefault();
var roomno_r = $('#roomno').val();
var tv_r = ($('#tv')[0].checked == true) ? "Y" : "";
var aircondition_r = ($('#aircondition')[0].checked == true) ? "Y" : "";

alert("btnsave JS : " + roomno_r + ", " + tv_r + ", " + aircondition_r);
$.ajax({
url : "room.php",
method : "POST",
Async : false,
data :{
buttonsave : 1 ,
roomno : roomno_r ,
tv : tv_r ,
aircondition: aircondition_r
},
success :function(result)
{
console.log(result);
}
});
});
});[/php]
[b]room.php[/b]
[php]<?php
include_once("_public.php");
include_once("sql/sql.php");
include_once("modele/modele.php");

$connexion = new connection();
$dbconnect = $connexion->connect();
$requeteSql = new requeteSql();

//ajouter une chambre
if(isset($_POST['buttonsave']))
{
$roomno = $_POST['roomno'];
$tv = !isset($_POST['tv']) ? "'" . $_POST['tv'] . "'" : NULL;
$aircondition = !isset($_POST['aircondition']) ? "'" . $_POST['aircondition'] . "'" : NULL;

echo "PHP : ".$roomno.",".$tv.",".$aircondition."<br>";
$findQuery = "SELECT * FROM rooms WHERE roomno = '".$roomno."'";

$resultat = $requeteSql->getRows2($findQuery);
if (sizeof($resultat) > 0){
echo "Existe déjà";
}
else{
//insert
$roomsSql = new roomsSql();
$rooms = new rooms();

$rooms->setRoomno($roomno);
$rooms->setTv($tv);
$rooms->setAircondition($aircondition);

$roomsSql->ajouter(serialize($rooms));
}
}
?>
<script type="text/javascript" src="js/jquery-1.12.4.js"></script>
<script type="text/javascript" src="js/roomListener.js"></script>
<form>
chambre :<input type="text" id="roomno" name="roomno" value=""/><br>
tv :<input type="checkbox" id="tv" name="tv" value="Y"/>
air conditione :<input type="checkbox" id="aircondition" name="aircondition" value="Y"/><br>
<input type="button" id="btnsave" name="btnsave" value="Ajouter"/>
</form>[/php]