I am trying to save data in database in background through a link, and to give download functionality to that link in front end. but it gives an error.
my script is -
<script>
$(document).ready(function(){
    $("#download").click(function(){
        var me = $(this), data = me.data('params');
        saveData(me);
});
function saveData(me){  
$.ajax({
       type: "POST",
       url: "download_counter.php",
       data: { client_id: "<? echo $client_id;?>", candidate_id: me }
    });
}
});
</script>
this is the link (It looks fine)
<a href="upload/<? echo $download;?>" id="download" data-params="{'ca_id':'<? echo $ca_id;?>'}"><button name="download"></button></a>
download_counter.php looks like -
<?
if (isset($_POST['candidate_id'])) { // Form has been submitted.
    $candidate_id = $_POST['candidate_id'];
    $client_id= $_POST['client_id'];
    $date = date("Y-m-d");
    echo "client - ".$client_id;
    echo "candidate - ".$candidate_id;
    $query = "INSERT INTO `downloads`(`client_id`, `candidate_id`, `download_date`) VALUES ('".$client_id."', '".$candidate_id."', '".$date."')";
    $result = mysql_query($query);  
}
?>
when i click the link, it lets download the file but database do not updates. Please help.
 
     
    