set references to objects in BlogFixture that CommentFixture can access and implement getOrder method in CommentFixture to setr the return value to 2 ensuring CommentFixture will be loaded after BlogFixture and then run in console 'php app/console doctrine:fixtures:load'
get the comments for one blog
update blog show action in controller to retrieve comments associated to the blog by using custom repository comment method defined before
create comment template(no need for controller) to show comments blog on show blog page