In the sales_flat_quote table, there is a store_id column. In my perspective the customer order in the front-end (website) and in the back-end, Magento creates each quote for different stores, if my understanding is correct.
While adding customer address, will Magento create a duplicate copy for each quote in the sales_flat_quote_address table?
How do the sales_flat_quote and sales_flat_quote_address tables work together during checkout?
When you add product to the cart, magento will have entries in
sales_flat_quote,sales_flat_quote_item and sales_flat_quote_address
ie: Carts are saved to the sales_flat_quote table
The items in the basket are saved to sales_flat_quote_item, linked by the quote's entity_id
Most of the entries in sales_flat_quote_address will be null when you create the cart. later it will be updated on checkout with proper addresses.
So when you remove a product from the cart, that product will be removed from the sales_flat_quote_item and item_qty,item_count and prices will be removed from the sales_flat_quote table.
This is the usual working flow. If you are not working on production please do truncate your quote tables and add product to the cart to see this changes. I think you might have missed the changes. Please do check the updated date of entries and you will definitely see the difference.
