Save html code to mysql table with php and jquery ajax - php

Question

Im trying to clone a div's content with jquery. After it is cloned i am sending it to a php page to be processed with Jquery Ajax. The php page saves it to a mysql database table. Then i need to retrieve it from the table on a different page and load it in another div. The mysql table cell is a blob that i save this html too. When i retrieve the table it echo's [object Object]. So i not usre if i am sending it to the save_invoice.php correctly or im not saving it to database correctly or last im not retrieving it correctly.
Html div: invoice.php
<div id="invoice_content">
<table>
<tr><td>Html Example</td></tr>
</table>
</div>
Jquery Code:
$(document).on('click', "#clone", function () {
var printContents = $("#invoice_content").clone(true, true);
//var $data = 'invoice=' + escape(printContents);
var $data = $(printContents).serialize();
$.ajax({ url: "functions/insert_html.php",
type: "POST",
dataType:"html",
data:$data,
success:function(obj){
alert(obj);
}
});
});
php: save_invoice.php
if (isset($_POST['invoice'])) {
$html = $_POST['invoice'];
$sql = "INSERT INTO `html table` (html)
VALUES ('" . mysql_real_escape_string($html) . "')";
if (mysqli_query($conn, $sql)) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);
}
php: view_invoice.php
if(isset($_GET)){
$id = $_GET['id'];
$sql = "SELECT html FROM `html table` WHERE id = '".$id."'";
$result = mysqli_query($conn, $sql);
while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
$html_id = $row["html"];
}
mysqli_close($conn);
}
<div id="invoice_content">
<?php echo $html_id; ?>
</div>