ruby on rails - How to convert model to migration -

i bit confused this. on creating model, thought produce migration gets pushed database. when type

rails g model userss name:string email:string group:integer

in model get:

class userss < activerecord::base end 

and in migration (20150619151857_create_usersses.rb)i get:

class createusersses < activerecord::migration   def change     create_table :usersses |t|       t.string :name       t.string :email       t.integer :group        t.timestamps     end   end end 

however, if type rails g model userss name:string email:string group:integer --migration=false

i same model, when run migration rails g migration userss, file not called ....create_userss.rb, called 20150619152316_userss.rb , contains:

class userss < activerecord::migration   def change   end end 

so why there difference in migration file?

i think confused how rails migration generators work. don't care @ models.

when run:

rails g model user name:string 

rails runs migration generator you:

rails g migration createusers name:string 

rails can figure out naming of migration kind of migration generate. createusers name:string create create table migration.

class createusers < activerecord::migration   def change     create_table :users |t|       t.string :name     end   end end 

addfootousers foo:int create migration alter users:

class addfootousers < activerecord::migration   def change     add_column :users, :foo, :int   end end 

rails not care if use camelcase or snakecase migration name in generator add_fields_to_users or addfieldstousers give same result.

also rails convention use singular form model names (user, fruit, car etc) important since lets rails automatically figure out connection between controllers , models.

even more important don't misspell common english words users since confuse every poor sod has maintain code.