Php mysql script error to generate xml file - php

Question

Good morning,
I created a script in php to export the data of a table of a db in mysql to xml.
With my script the file is created, but on the screen I always get this error:
Notice: Object of class mysqli_result could not be converted to int in C:\xampp\htdocs\testxml001\exportxml.php on line 9
Below is also the script in php
<?php
$conn = mysqli_connect("localhost", "root", "", "dbtest001");
if(!$conn){
echo "DB not Connected...";
}
else{
$result=mysqli_query($conn, "Select * from table001");
if($result>0){
$xml = new DOMDocument("1.0");
// It will format the output in xml format otherwise
// the output will be in a single row
$xml->formatOutput=true;
$dbtest001=$xml->createElement("table001");
$xml->appendChild($dbtest001);
while($row=mysqli_fetch_array($result)){
$RECORD=$xml->createElement("RECORD");
$dbtest001->appendChild($RECORD);
$ID=$xml->createElement("ID", $row['ID']);
$RECORD->appendChild($ID);
$category=$xml->createElement("category", $row['category']);
$RECORD->appendChild($category);
$ad_zip=$xml->createElement("ad_zip", $row['ad_zip']);
$RECORD->appendChild($ad_zip);
$ad_city=$xml->createElement("ad_city", $row['ad_city']);
$RECORD->appendChild($ad_city);
$ad_phone=$xml->createElement("ad_phone", $row['ad_phone']);
$RECORD->appendChild($ad_phone);
$email=$xml->createElement("email", $row['email']);
$RECORD->appendChild($email);
}
echo "<xmp>".$xml->saveXML()."</xmp>";
$xml->save("report.xml");
}
else{
echo "error";
}
}
?>