Hi please can someone help me to resolve these problem,

"please check your query"

these is my code php.

<?php

$hostname = "localhost";

$username = "root";

$password = "";

$dbname = "courrier";

$db = new mysqli ($hostname, $username,$password, $dbname) or die ("unable to connect");

if (!$db)

{

die("connection failed" . mysqli_connect_error());

}

else

{ 

if (isset($_POST['update'])) 

{

$ID=$_GET['idv'];

$N_Enreg=$_POST['N_Enreg'];

    $exp=$_POST['exp'];

    $obj=$_POST['obj'];

    $datet=$_POST['datet'];

    $ser=$_POST['ser'];

    $dateA=$_POST['dateA'];

    $ins_w=$_POST['ins_w'];

    $ins_G=$_POST['ins_G'];

    $obs=$_POST['obs'];

    //$etat1=$_POST['etat1'];

$query = "UPDATE tab_suiver SET N_Enreg='$N_Enreg',Expéditeur=' $exp',Objet='$obj',Date_Arrivée='$datet',Service='$ser',date_Affectation='$dateA',Instruction_wali='$ins_w',Instruction_Gouverneur='$ins_G',Observation='$obs', WHERE ID='$ID' ";

$result = mysqli_query($db,$query);

if ($result) 

{

header("refresh:1; url=index.php");

}

else

{

echo 'please check your query';

}

}

else

{

header("location:index.php");

}

}

  ?>