Can not update product stock using Webservices

[Devlord1]

Hi,

 

why is it so difficult to just update the stock quantity of a product using the webservices?

 

I'm getting :

 

<?xml version="1.0" encoding="UTF-8"?>

<prestashop xmlns:xlink="http://www.w3.org/1999/xlink">

<errors>

<error>

<code><![CDATA[93]]></code>

<message><![CDATA[parameter "quantity" not writable. Please remove this attribute of this XML]]></message>

</error>

</errors>

</prestashop>

 

How on earth can update the stock of a product by Product id? Are there other methods?

Can i add a PHP file in the root of the site and add a own piece of code to update product stock, because the webservices with all it's strange limits and bugs is really a pain :-(

 

I really hope someone can help me. Thank you!

 

Dev.