note.txt

HTTP Verb	Path	        Controller#Action	            Used for
GET	/photos	                photos#index	            display a list of all photos
GET	/photos/new	            photos#new	                return an HTML form for creating a new photo
POST	/photos	            photos#create	            create a new photo
GET	/photos/:id	            photos#show	                display a specific photo
GET	/photos/:id/edit	    photos#edit     	        return an HTML form for editing a photo
PATCH/PUT	/photos/:id	    photos#update	            update a specific photo
DELETE	/photos/:id	        photos#destroy	            delete a specific photo



//associated
user.microposts.create(arg) Creates a micropost associated with user
user.microposts.create!(arg) Creates a micropost associated with user (exception on failure)
user.microposts.build(arg) Returns a new Micropost object associated with user


private method 
+ truy cap dc tu method trong cung classs (static)
+ truy cap dc tu lop ke thua 
+ truy cap dc tu include mmodule

public default truy cap tu bat ky dau 
protected
giong private nhung chi duoc goi khi khoi tao doi tuong


rails active_storage:install migrate db tao file de upload image