I want to update multiple rows which are selected through checkbox
<p>Am selecting rows via checkbox through this loop applied on select query.   </p>

<pre><code> while($row = mysql_fetch_array($result, MYSQL_ASSOC))
  {
    echo '&lt;tr&gt;';
    $res = $row['userid'];
    echo "&lt;td&gt;&lt;input type='checkbox' name='chk[]' value='$res'&gt;&lt;/td&gt;";

   echo 
    "&lt;td&gt;ID :{$row['userid']}  &lt;br&gt; &lt;/td&gt;".
    "&lt;td&gt;ID :{$row['id']}  &lt;br&gt; &lt;/td&gt;".
    "&lt;td&gt;{$row['name']}  &lt;br&gt; &lt;/td&gt;".
    "&lt;td&gt;{$row['shifttime']}  &lt;br&gt; &lt;/td&gt;&lt;/tr&gt;";
      $i++;    
   } 
</code></pre>

<p>Then want to update my db through the id's am getting from checkboxes</p>

<pre><code> if(isset($_POST['chk'])){
    $shift=$_POST['shiftTime'];
    $chkarray = $_POST['chk'];
    foreach ($chkarray as $val) {
    $sql = "UPDATE user_shift_test2 SET shifttime ='$shift' WHERE id='" . $_POST["chk"] . "' ";
    $result = mysql_query( $sql, $conn);
</code></pre>

<p>Thanks.</p>