title: how to convert sql query to django queryset?
body: <p>i have two tables like categories and items  in models items has foreign key of categories,here we have 4 categories and 12 items where each category has 3 items how to write a query set to get query set to get items with same category
  i know how to write Sql query (<code>select * from category where category_id =1;</code>). how to write it in d'jango query set.</p>