Php Code for Inserting images in each row

I have need help in the below coding, right now it update the image every time i insert new trough form, i need it should update/insert image in each row not update the same image, kindly help .. code is below

<?PHP
if(isset($_POST['add_value'])){
    $sql ="INSERT INTO tb_special_offer (offer_price, offer_title, offer_desc, offer_link) VALUES ('"
        .addslashes($_REQUE开发者_高级运维ST['offer_price'])."', '"
        .addslashes($_REQUEST['offer_title'])."', '"
        .addslashes($_REQUEST['offer_desc'])."', '"
        .addslashes($_REQUEST[offer_link])."')";
    $qry = mysql_query($sql) or die (mysql_error());
    //Image

    if($_FILES['offer_img']['name']){
        $uploaded_image = $_FILES['offer_img']['name'];
        $imgpath = "userfiles/specialoffer/";
        if(file_exists($imgpath.$uploaded_image)) unlink($imgpath.$uploaded_image);
        if(!move_uploaded_file($_FILES['offer_img']['tmp_name'], $imgpath.$uploaded_image)){
            $errMsg= "UPLOAD ERROR..!!!".$_FILES['offer_img']['name'];
        }
        else {
            $sql = "update tb_special_offer set offer_img='$uploaded_image'   ";
            $qry = mysql_query($sql) or die (mysql_error());
        }
    }

    header("Location: specialoffer?msg=Special Offer Added Successfully!");
    exit;
}
?>

Your query means that all rows in your database get that image as value for the offer_img column. Update means just that: update a row.

If you want to update a specific row, not every row, do something like this:

update tb_special_offer set offer_img='$uploaded_image' where id=xxxx

But I suspect you want to use an INSERT query. As you've not provided any more info I cannot write it for you, but it should be easy. Just read the manual, but it boils down to something like

INSERT into tb_special_offer (offer_img) VALUES ('$uploaded_image')