อยากทราบสาเหตุและวิธีแก้ปัญหา การเกิด Warning ใน php connect Mysqli

$str = "UPDATE rleave SET status = 'APPROVE' WHERE id_leave = '".$check."' ";
$Execute = mysqli_query($Connect,$str);
$ExecuteResult = mysqli_fetch_assoc($Execute);

        header("Content-type: application/json; charset=utf8");
	$Connect = mysqli_connect("localhost","root","","cmc")or die(mysqli_error());
	error_reporting( error_reporting() & ~E_NOTICE );
	mysqli_query($Connect,"SET NAMES UTF8");
	$check = $_POST["noleave"];
	$str = "UPDATE rleave SET status = 'APPROVE' WHERE id_leave = '".$check."' ";
	$Execute = mysqli_query($Connect,$str);
	if($Execute){
		$arr['Status'] = "1";
	}else{
		$arr['Status'] = "0";
	}
	mysqli_close($Connect);
	echo json_encode($arr);