You would need to alter the SELECT statements where you want this to happen ...
And example of how to make the Sold Out last would be:
Code:
SELECT products_id, products_model, products_status, products_quantity, (products_quantity > 0) AS sort_sold from products order by sort_sold DESC, products_model
This pulls the fields products_id, products_model, products_status, products_quantity and creates a new one, sort_sold, and then in the ORDER the sort_sold DESC before the products_model of the ORDER statement puts the Sold Out Products, products with products_quantity <= 0, last ... but it is in the ORDER of the products_model ...
NOTE: products_quantity does not need to be part of the SELECT, it is just there to test this ...