title: WooCommerce, WP all import - Find product ID by attribute value
body: <p>I want to update WooCommerce products by the WP All import. I have 2 independent xml files (from the first one I'm getting prices, from the second one descriptions). For some reasons product's <code>_sku</code> is <code>{code}</code> from the first one xml not <code>{ean}</code>. So I put <code>{ean}</code> into product attribute <code>pa_ean</code> to match the products from the first one and the second one xml.
  Now I don't know how to write the php function to return <code>product_id</code> so WP All import could update right products with right descriptions.</p>