View product based on category and subcategory

i am developing a eCommerce site. In this I have Category and its Sub-category. Some Category have its Sub-category and Some Category have not its Sub-category. Example I have category of 'Mobile Phones' its have no Sub-category. and the Category 'Home Appliances'  have sub category like 'Freeze, Air Cooler' etc. I have view product page I want to view the product based on category if its has no subcategory . and  if the category have subcategory then I want to load its sub-category first after that I want to view the product based on the its sub-category not based on Category. In category table I have a column name 'addSubCat' that specifies the category has a sub-category or not. if the column value is 1 then it has subcategory and if it has 0 then no sub-category