Subdomain with same database

Hi,
I am currently working on one shopping cart site where we have 4 major categories of products.I have used Woocommerce plugin for shopping cart. Currently I am working on localhost & it works fine for me. But I want to make the site run on four different sub-domains like e.g. product1.maindomain.com, product2.maindomain.com,product3.maindomain.com & product4.maindomain.com. But since its a single shopping cart site I need to use single database for all those products. How can I manage this?
Is there any other way round? Let me know asap since I need to deliver it in short timeline.