How are partial refunds stored in the WooCommerce Database?

Partial refund orders are stored in database like normal ones: In wp_posts table with a 'post_type' = 'shop_order_refund' and a 'post_parent' = order_ID (number), where the order_ID is the reference to the original 'shop_order'.

To find out which one of this refunds are partial, you need the _refund_amount amount value that you can find under wp_post_meta for this 'refund_order' and his corresponding 'shop_order' with the _order_total value too:

if ( 'refund_order' => _refund_amount ) != ( 'shop_order' => _order_total ) :then it's partial.

if ( 'refund_order' => _refund_amount ) == ( 'shop_order' => _order_total ) :then it's normal (not partial).

Notes:

• You can have one or many partial refunds for one order.
• There is for refund orders an _order_total item in wp_postmeta table with a negative value that is always reflecting the positive value of _refund_amount item. This _order_total value has nothing to do with the related parent 'shop_order' => '_order_total' value.

  It's the opposite (negative) value of the related parent 'shop_order' => '_order_total' value only when refund order IS NOT PARTIAL.

• In wp_woocommerce_order_items and wp_woocommerce_order_itemmeta tables, there is related detailed data concerning products in orders and refunded orders...