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Julien Estebane

2012-Dec-26 02:25 UTC

has_to and belongs_to realtionships are not showing up in database

Hello,

I am having what I might think is a basic problem...I can''t get the 
relationships of has_many and belongs_to mapped out correctly in the 
database. I would expect, according to my MODEL and MIGRATION, that there 
would be a desktop_id in the states and environments DATABASE table ?

How can I get the desktop_id, state_id and environment_id columns mapped 
out in the tables ?

I ran rake db:migrate before going to the rails console and checking the 
tables...

MODEL:
------

user@user-DevMachine:~/dev/myapp/app/models$ cat engine.rb 
class Engine < ActiveRecord::Base
  # attr_accessible :title, :body
  belongs_to :environment
  belongs_to :state
end
user@user-DevMachine:~/dev/myapp/app/models$ cat environment.rb 
class Environment < ActiveRecord::Base
  attr_accessible :description
  has_many :engines
end
user@user-DevMachine:~/dev/myapp/app/models$ cat state.rb 
class State < ActiveRecord::Base
  attr_accessible :description
  has_many :engines
end



MIGRATION:
----------

user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
20121225230016_create_engines.rb
class CreateEngines < ActiveRecord::Migration
  def change
    create_table :engines do |t|

      t.timestamps
    end
  end
end
user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
20121225230034_create_states.rb
class CreateStates < ActiveRecord::Migration
  def change
    create_table :states do |t|
      t.string :description

      t.timestamps
    end
  end
end
user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
20121225230118_create_environments.rb
class CreateEnvironments < ActiveRecord::Migration
  def change
    create_table :environments do |t|
      t.string :description
      t.timestamps
    end
  end
end
user@user-DevMachine:~/dev/myapp/db/migrate$ 



DATABASE:
---------

user@user-DevMachine:~/dev/myapp/db/migrate$ rails console
Loading development environment (Rails 3.2.9)
1.9.3-p327 :001 > ActiveRecord::Base.connection.execute("SELECT * FROM 
engines")
   (1.1ms)  SELECT * FROM engines
 => [{"id"=>1, "created_at"=>"2012-12-26
01:26:38.789476",
"updated_at"=>"2012-12-26 01:26:38.789476", 0=>1,
1=>"2012-12-26
01:26:38.789476", 2=>"2012-12-26 01:26:38.789476"}] 
1.9.3-p327 :002 > ActiveRecord::Base.connection.execute("SELECT * FROM 
environments")
   (0.3ms)  SELECT * FROM environments
 => [{"id"=>1, "description"=>"warm",
"created_at"=>"2012-12-26
01:27:40.968920", "updated_at"=>"2012-12-26
01:27:40.968920", 0=>1,
1=>"warm", 2=>"2012-12-26 01:27:40.968920",
3=>"2012-12-26
01:27:40.968920"}, {"id"=>2,
"description"=>"cold",
"created_at"=>"2012-12-26 01:27:41.055711",
"updated_at"=>"2012-12-26
01:27:41.055711", 0=>2, 1=>"cold", 2=>"2012-12-26
01:27:41.055711",
3=>"2012-12-26 01:27:41.055711"}, {"id"=>3,
"description"=>"hot",
"created_at"=>"2012-12-26 01:27:41.129397",
"updated_at"=>"2012-12-26
01:27:41.129397", 0=>3, 1=>"hot", 2=>"2012-12-26
01:27:41.129397",
3=>"2012-12-26 01:27:41.129397"}, {"id"=>4,
"description"=>"freezing",
"created_at"=>"2012-12-26 01:27:41.284936",
"updated_at"=>"2012-12-26
01:27:41.284936", 0=>4, 1=>"freezing",
2=>"2012-12-26 01:27:41.284936",
3=>"2012-12-26 01:27:41.284936"}] 
1.9.3-p327 :003 > ActiveRecord::Base.connection.execute("SELECT * FROM 
states")
   (0.4ms)  SELECT * FROM states
 => [{"id"=>1, "description"=>"running",
"created_at"=>"2012-12-26
01:27:40.452140", "updated_at"=>"2012-12-26
01:27:40.452140", 0=>1,
1=>"running", 2=>"2012-12-26 01:27:40.452140",
3=>"2012-12-26
01:27:40.452140"}, {"id"=>2,
"description"=>"stopping",
"created_at"=>"2012-12-26 01:27:40.536188",
"updated_at"=>"2012-12-26
01:27:40.536188", 0=>2, 1=>"stopping",
2=>"2012-12-26 01:27:40.536188",
3=>"2012-12-26 01:27:40.536188"}, {"id"=>3,
"description"=>"restarting",
"created_at"=>"2012-12-26 01:27:40.613507",
"updated_at"=>"2012-12-26
01:27:40.613507", 0=>3, 1=>"restarting",
2=>"2012-12-26 01:27:40.613507",
3=>"2012-12-26 01:27:40.613507"}, {"id"=>4,
"description"=>"creating",
"created_at"=>"2012-12-26 01:27:40.688855",
"updated_at"=>"2012-12-26
01:27:40.688855", 0=>4, 1=>"creating",
2=>"2012-12-26 01:27:40.688855",
3=>"2012-12-26 01:27:40.688855"}, {"id"=>5,
"description"=>"destroying",
"created_at"=>"2012-12-26 01:27:40.768293",
"updated_at"=>"2012-12-26
01:27:40.768293", 0=>5, 1=>"destroying",
2=>"2012-12-26 01:27:40.768293",
3=>"2012-12-26 01:27:40.768293"}] 
1.9.3-p327 :004 > 


Thanks 

Julien Estebane

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Frederick Cheung

2012-Dec-26 13:27 UTC

head link

Re: has_to and belongs_to realtionships are not showing up in database

On Dec 26, 2:25 am, Julien Estebane
<julienesteb...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:> Hello,
>
> I am having what I might think is a basic problem...I can''t get
the
> relationships of has_many and belongs_to mapped out correctly in the
> database. I would expect, according to my MODEL and MIGRATION, that there
> would be a desktop_id in the states and environments DATABASE table ?
>
> How can I get the desktop_id, state_id and environment_id columns mapped
> out in the tables ?
There need to be statements in your migrations to add those columns -
rails won''t look at the models and work it out from the associations
in there.

You may be confusing things with datamapper (that does do this I
think) or with the fact that if you do rails g model foo
belongs_to:bar then rails will add the belongs_to to the model and the
migration.

Fred.>
> I ran rake db:migrate before going to the rails console and checking the
> tables...
>
> MODEL:
> ------
>
> user@user-DevMachine:~/dev/myapp/app/models$ cat engine.rb
> class Engine < ActiveRecord::Base
>   # attr_accessible :title, :body
>   belongs_to :environment
>   belongs_to :state
> end
> user@user-DevMachine:~/dev/myapp/app/models$ cat environment.rb
> class Environment < ActiveRecord::Base
>   attr_accessible :description
>   has_many :engines
> end
> user@user-DevMachine:~/dev/myapp/app/models$ cat state.rb
> class State < ActiveRecord::Base
>   attr_accessible :description
>   has_many :engines
> end
>
> MIGRATION:
> ----------
>
> user@user-DevMachine:~/dev/myapp/db/migrate$ cat
> 20121225230016_create_engines.rb
> class CreateEngines < ActiveRecord::Migration
>   def change
>     create_table :engines do |t|
>
>       t.timestamps
>     end
>   end
> end
> user@user-DevMachine:~/dev/myapp/db/migrate$ cat
> 20121225230034_create_states.rb
> class CreateStates < ActiveRecord::Migration
>   def change
>     create_table :states do |t|
>       t.string :description
>
>       t.timestamps
>     end
>   end
> end
> user@user-DevMachine:~/dev/myapp/db/migrate$ cat
> 20121225230118_create_environments.rb
> class CreateEnvironments < ActiveRecord::Migration
>   def change
>     create_table :environments do |t|
>       t.string :description
>       t.timestamps
>     end
>   end
> end
> user@user-DevMachine:~/dev/myapp/db/migrate$
>
> DATABASE:
> ---------
>
> user@user-DevMachine:~/dev/myapp/db/migrate$ rails console
> Loading development environment (Rails 3.2.9)
> 1.9.3-p327 :001 > ActiveRecord::Base.connection.execute("SELECT *
FROM
> engines")
>    (1.1ms)  SELECT * FROM engines
>  => [{"id"=>1, "created_at"=>"2012-12-26
01:26:38.789476",
> "updated_at"=>"2012-12-26 01:26:38.789476", 0=>1,
1=>"2012-12-26
> 01:26:38.789476", 2=>"2012-12-26 01:26:38.789476"}]
> 1.9.3-p327 :002 > ActiveRecord::Base.connection.execute("SELECT *
FROM
> environments")
>    (0.3ms)  SELECT * FROM environments
>  => [{"id"=>1,
"description"=>"warm",
"created_at"=>"2012-12-26
> 01:27:40.968920", "updated_at"=>"2012-12-26
01:27:40.968920", 0=>1,
> 1=>"warm", 2=>"2012-12-26 01:27:40.968920",
3=>"2012-12-26
> 01:27:40.968920"}, {"id"=>2,
"description"=>"cold",
> "created_at"=>"2012-12-26 01:27:41.055711",
"updated_at"=>"2012-12-26
> 01:27:41.055711", 0=>2, 1=>"cold",
2=>"2012-12-26 01:27:41.055711",
> 3=>"2012-12-26 01:27:41.055711"}, {"id"=>3,
"description"=>"hot",
> "created_at"=>"2012-12-26 01:27:41.129397",
"updated_at"=>"2012-12-26
> 01:27:41.129397", 0=>3, 1=>"hot",
2=>"2012-12-26 01:27:41.129397",
> 3=>"2012-12-26 01:27:41.129397"}, {"id"=>4,
"description"=>"freezing",
> "created_at"=>"2012-12-26 01:27:41.284936",
"updated_at"=>"2012-12-26
> 01:27:41.284936", 0=>4, 1=>"freezing",
2=>"2012-12-26 01:27:41.284936",
> 3=>"2012-12-26 01:27:41.284936"}]
> 1.9.3-p327 :003 > ActiveRecord::Base.connection.execute("SELECT *
FROM
> states")
>    (0.4ms)  SELECT * FROM states
>  => [{"id"=>1,
"description"=>"running",
"created_at"=>"2012-12-26
> 01:27:40.452140", "updated_at"=>"2012-12-26
01:27:40.452140", 0=>1,
> 1=>"running", 2=>"2012-12-26 01:27:40.452140",
3=>"2012-12-26
> 01:27:40.452140"}, {"id"=>2,
"description"=>"stopping",
> "created_at"=>"2012-12-26 01:27:40.536188",
"updated_at"=>"2012-12-26
> 01:27:40.536188", 0=>2, 1=>"stopping",
2=>"2012-12-26 01:27:40.536188",
> 3=>"2012-12-26 01:27:40.536188"}, {"id"=>3,
"description"=>"restarting",
> "created_at"=>"2012-12-26 01:27:40.613507",
"updated_at"=>"2012-12-26
> 01:27:40.613507", 0=>3, 1=>"restarting",
2=>"2012-12-26 01:27:40.613507",
> 3=>"2012-12-26 01:27:40.613507"}, {"id"=>4,
"description"=>"creating",
> "created_at"=>"2012-12-26 01:27:40.688855",
"updated_at"=>"2012-12-26
> 01:27:40.688855", 0=>4, 1=>"creating",
2=>"2012-12-26 01:27:40.688855",
> 3=>"2012-12-26 01:27:40.688855"}, {"id"=>5,
"description"=>"destroying",
> "created_at"=>"2012-12-26 01:27:40.768293",
"updated_at"=>"2012-12-26
> 01:27:40.768293", 0=>5, 1=>"destroying",
2=>"2012-12-26 01:27:40.768293",
> 3=>"2012-12-26 01:27:40.768293"}]
> 1.9.3-p327 :004 >
>
> Thanks
>
> Julien Estebane
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Julien Estebane

2012-Dec-26 18:19 UTC

head link

Re: has_to and belongs_to realtionships are not showing up in database

Hello Frederick,

As you suggested, i attempted to include this in my scaffold, but when I 
rake db:migrate, I get the error:


user@user-user:~/dev/myapp$ rails generate scaffold engine 
belongs_to:environment belongs_to:state
      invoke  active_record
      create    db/migrate/20121226181404_create_engines.rb
      create    app/models/engine.rb
      invoke    test_unit
      create      test/unit/engine_test.rb
      create      test/fixtures/engines.yml
      invoke  resource_route
       route    resources :engines
      invoke  scaffold_controller
      create    app/controllers/engines_controller.rb
      invoke    erb
      create      app/views/engines
      create      app/views/engines/index.html.erb
      create      app/views/engines/edit.html.erb
      create      app/views/engines/show.html.erb
      create      app/views/engines/new.html.erb
      create      app/views/engines/_form.html.erb
      invoke    test_unit
      create      test/functional/engines_controller_test.rb
      invoke    helper
      create      app/helpers/engines_helper.rb
      invoke      test_unit
      create        test/unit/helpers/engines_helper_test.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/engines.js.coffee
      invoke    scss
      create      app/assets/stylesheets/engines.css.scss
      invoke  scss
      create    app/assets/stylesheets/scaffolds.css.scss
user@user-user:~/dev/myapp$ rails generate scaffold environment 
description:string has_many:engines
      invoke  active_record
      create    db/migrate/20121226181441_create_environments.rb
      create    app/models/environment.rb
      invoke    test_unit
      create      test/unit/environment_test.rb
      create      test/fixtures/environments.yml
      invoke  resource_route
       route    resources :environments
      invoke  scaffold_controller
      create    app/controllers/environments_controller.rb
      invoke    erb
      create      app/views/environments
      create      app/views/environments/index.html.erb
      create      app/views/environments/edit.html.erb
      create      app/views/environments/show.html.erb
      create      app/views/environments/new.html.erb
      create      app/views/environments/_form.html.erb
      invoke    test_unit
      create      test/functional/environments_controller_test.rb
      invoke    helper
      create      app/helpers/environments_helper.rb
      invoke      test_unit
      create        test/unit/helpers/environments_helper_test.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/environments.js.coffee
      invoke    scss
      create      app/assets/stylesheets/environments.css.scss
      invoke  scss
   identical    app/assets/stylesheets/scaffolds.css.scss
user@user-user:~/dev/myapp$ rails generate scaffold state 
description:string has_many:engines
      invoke  active_record
      create    db/migrate/20121226181504_create_states.rb
      create    app/models/state.rb
      invoke    test_unit
      create      test/unit/state_test.rb
      create      test/fixtures/states.yml
      invoke  resource_route
       route    resources :states
      invoke  scaffold_controller
      create    app/controllers/states_controller.rb
      invoke    erb
      create      app/views/states
      create      app/views/states/index.html.erb
      create      app/views/states/edit.html.erb
      create      app/views/states/show.html.erb
      create      app/views/states/new.html.erb
      create      app/views/states/_form.html.erb
      invoke    test_unit
      create      test/functional/states_controller_test.rb
      invoke    helper
      create      app/helpers/states_helper.rb
      invoke      test_unit
      create        test/unit/helpers/states_helper_test.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/states.js.coffee
      invoke    scss
      create      app/assets/stylesheets/states.css.scss
      invoke  scss
   identical    app/assets/stylesheets/scaffolds.css.scss
user@user-user:~/dev/myapp$ rake db:create
user@user-user:~/dev/myapp$ rake db:migrate
==  CreateEngines: migrating 
=================================================-- create_table(:engines)
rake aborted!
An error has occurred, this and all later migrations canceled:

undefined method `environment'' for 
#<ActiveRecord::ConnectionAdapters::TableDefinition:0x00000001ca2ff0>
/home/user/temp/project/db/migrate/20121226181404_create_engines.rb:4:in 
`block in change''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/schema_statements.rb:160:in
`create_table''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:466:in
`block in method_missing''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:438:in
`block in say_with_time''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:438:in
`say_with_time''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:458:in
`method_missing''
/home/user/temp/project/db/migrate/20121226181404_create_engines.rb:3:in 
`change''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:407:in
`block (2 levels) in migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:407:in
`block in migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:129:in
`with_connection''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:389:in
`migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:528:in
`migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:720:in
`block (2 levels) in migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:775:in
`call''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:775:in
`block in ddl_transaction''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in
`transaction''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/transactions.rb:208:in
`transaction''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:775:in
`ddl_transaction''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:719:in
`block in migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:700:in
`each''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:700:in
`migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:570:in
`up''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/migration.rb:551:in
`migrate''
/home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_record/railties/databases.rake:179:in
`block (2 levels) in <top (required)>''
/home/user/.rvm/gems/ruby-1.9.3-p327/bin/ruby_noexec_wrapper:14:in
`eval''
/home/user/.rvm/gems/ruby-1.9.3-p327/bin/ruby_noexec_wrapper:14:in
`<main>''
Tasks: TOP => db:migrate
(See full trace by running task with --trace)


On Wednesday, December 26, 2012 8:27:27 AM UTC-5, Frederick Cheung
wrote:>
>
>
> On Dec 26, 2:25 am, Julien Estebane
<julienesteb...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > Hello, 
> > 
> > I am having what I might think is a basic problem...I can''t
get the
> > relationships of has_many and belongs_to mapped out correctly in the 
> > database. I would expect, according to my MODEL and MIGRATION, that 
> there 
> > would be a desktop_id in the states and environments DATABASE table ? 
> > 
> > How can I get the desktop_id, state_id and environment_id columns
mapped
> > out in the tables ? 
>
> There need to be statements in your migrations to add those columns - 
> rails won''t look at the models and work it out from the
associations
> in there. 
>
> You may be confusing things with datamapper (that does do this I 
> think) or with the fact that if you do rails g model foo 
> belongs_to:bar then rails will add the belongs_to to the model and the 
> migration. 
>
> Fred. 
> > 
> > I ran rake db:migrate before going to the rails console and checking
the
> > tables... 
> > 
> > MODEL: 
> > ------ 
> > 
> > user@user-DevMachine:~/dev/myapp/app/models$ cat engine.rb 
> > class Engine < ActiveRecord::Base 
> >   # attr_accessible :title, :body 
> >   belongs_to :environment 
> >   belongs_to :state 
> > end 
> > user@user-DevMachine:~/dev/myapp/app/models$ cat environment.rb 
> > class Environment < ActiveRecord::Base 
> >   attr_accessible :description 
> >   has_many :engines 
> > end 
> > user@user-DevMachine:~/dev/myapp/app/models$ cat state.rb 
> > class State < ActiveRecord::Base 
> >   attr_accessible :description 
> >   has_many :engines 
> > end 
> > 
> > MIGRATION: 
> > ---------- 
> > 
> > user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
> > 20121225230016_create_engines.rb 
> > class CreateEngines < ActiveRecord::Migration 
> >   def change 
> >     create_table :engines do |t| 
> > 
> >       t.timestamps 
> >     end 
> >   end 
> > end 
> > user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
> > 20121225230034_create_states.rb 
> > class CreateStates < ActiveRecord::Migration 
> >   def change 
> >     create_table :states do |t| 
> >       t.string :description 
> > 
> >       t.timestamps 
> >     end 
> >   end 
> > end 
> > user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
> > 20121225230118_create_environments.rb 
> > class CreateEnvironments < ActiveRecord::Migration 
> >   def change 
> >     create_table :environments do |t| 
> >       t.string :description 
> >       t.timestamps 
> >     end 
> >   end 
> > end 
> > user@user-DevMachine:~/dev/myapp/db/migrate$ 
> > 
> > DATABASE: 
> > --------- 
> > 
> > user@user-DevMachine:~/dev/myapp/db/migrate$ rails console 
> > Loading development environment (Rails 3.2.9) 
> > 1.9.3-p327 :001 >
ActiveRecord::Base.connection.execute("SELECT * FROM
> > engines") 
> >    (1.1ms)  SELECT * FROM engines 
> >  => [{"id"=>1,
"created_at"=>"2012-12-26 01:26:38.789476",
> > "updated_at"=>"2012-12-26 01:26:38.789476",
0=>1, 1=>"2012-12-26
> > 01:26:38.789476", 2=>"2012-12-26 01:26:38.789476"}] 
> > 1.9.3-p327 :002 >
ActiveRecord::Base.connection.execute("SELECT * FROM
> > environments") 
> >    (0.3ms)  SELECT * FROM environments 
> >  => [{"id"=>1,
"description"=>"warm",
"created_at"=>"2012-12-26
> > 01:27:40.968920", "updated_at"=>"2012-12-26
01:27:40.968920", 0=>1,
> > 1=>"warm", 2=>"2012-12-26 01:27:40.968920",
3=>"2012-12-26
> > 01:27:40.968920"}, {"id"=>2,
"description"=>"cold",
> > "created_at"=>"2012-12-26 01:27:41.055711",
"updated_at"=>"2012-12-26
> > 01:27:41.055711", 0=>2, 1=>"cold",
2=>"2012-12-26 01:27:41.055711",
> > 3=>"2012-12-26 01:27:41.055711"}, {"id"=>3,
"description"=>"hot",
> > "created_at"=>"2012-12-26 01:27:41.129397",
"updated_at"=>"2012-12-26
> > 01:27:41.129397", 0=>3, 1=>"hot",
2=>"2012-12-26 01:27:41.129397",
> > 3=>"2012-12-26 01:27:41.129397"}, {"id"=>4,
"description"=>"freezing",
> > "created_at"=>"2012-12-26 01:27:41.284936",
"updated_at"=>"2012-12-26
> > 01:27:41.284936", 0=>4, 1=>"freezing",
2=>"2012-12-26 01:27:41.284936",
> > 3=>"2012-12-26 01:27:41.284936"}] 
> > 1.9.3-p327 :003 >
ActiveRecord::Base.connection.execute("SELECT * FROM
> > states") 
> >    (0.4ms)  SELECT * FROM states 
> >  => [{"id"=>1,
"description"=>"running",
"created_at"=>"2012-12-26
> > 01:27:40.452140", "updated_at"=>"2012-12-26
01:27:40.452140", 0=>1,
> > 1=>"running", 2=>"2012-12-26
01:27:40.452140", 3=>"2012-12-26
> > 01:27:40.452140"}, {"id"=>2,
"description"=>"stopping",
> > "created_at"=>"2012-12-26 01:27:40.536188",
"updated_at"=>"2012-12-26
> > 01:27:40.536188", 0=>2, 1=>"stopping",
2=>"2012-12-26 01:27:40.536188",
> > 3=>"2012-12-26 01:27:40.536188"}, {"id"=>3,
"description"=>"restarting",
> > "created_at"=>"2012-12-26 01:27:40.613507",
"updated_at"=>"2012-12-26
> > 01:27:40.613507", 0=>3, 1=>"restarting",
2=>"2012-12-26
> 01:27:40.613507", 
> > 3=>"2012-12-26 01:27:40.613507"}, {"id"=>4,
"description"=>"creating",
> > "created_at"=>"2012-12-26 01:27:40.688855",
"updated_at"=>"2012-12-26
> > 01:27:40.688855", 0=>4, 1=>"creating",
2=>"2012-12-26 01:27:40.688855",
> > 3=>"2012-12-26 01:27:40.688855"}, {"id"=>5,
"description"=>"destroying",
> > "created_at"=>"2012-12-26 01:27:40.768293",
"updated_at"=>"2012-12-26
> > 01:27:40.768293", 0=>5, 1=>"destroying",
2=>"2012-12-26
> 01:27:40.768293", 
> > 3=>"2012-12-26 01:27:40.768293"}] 
> > 1.9.3-p327 :004 > 
> > 
> > Thanks 
> > 
> > Julien Estebane 
>
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Frederick Cheung

2012-Dec-26 19:27 UTC

head link

Re: has_to and belongs_to realtionships are not showing up in database

On Dec 26, 6:19 pm, Julien Estebane
<julienesteb...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:> Hello Frederick,
>
> As you suggested, i attempted to include this in my scaffold, but when I
> rake db:migrate, I get the error:
>
You probably don''t want to include the has_many - since that requires
a column on the other table. Other than that, take a look at the
generated migration.

To be honest i don''t bother with the belongs_to shortcuts for
migrations - I just add the columns as ''normal'' columns and
then edit
the model

Fred
> user@user-user:~/dev/myapp$ rails generate scaffold engine
> belongs_to:environment belongs_to:state
>       invoke  active_record
>       create    db/migrate/20121226181404_create_engines.rb
>       create    app/models/engine.rb
>       invoke    test_unit
>       create      test/unit/engine_test.rb
>       create      test/fixtures/engines.yml
>       invoke  resource_route
>        route    resources :engines
>       invoke  scaffold_controller
>       create    app/controllers/engines_controller.rb
>       invoke    erb
>       create      app/views/engines
>       create      app/views/engines/index.html.erb
>       create      app/views/engines/edit.html.erb
>       create      app/views/engines/show.html.erb
>       create      app/views/engines/new.html.erb
>       create      app/views/engines/_form.html.erb
>       invoke    test_unit
>       create      test/functional/engines_controller_test.rb
>       invoke    helper
>       create      app/helpers/engines_helper.rb
>       invoke      test_unit
>       create        test/unit/helpers/engines_helper_test.rb
>       invoke  assets
>       invoke    coffee
>       create      app/assets/javascripts/engines.js.coffee
>       invoke    scss
>       create      app/assets/stylesheets/engines.css.scss
>       invoke  scss
>       create    app/assets/stylesheets/scaffolds.css.scss
> user@user-user:~/dev/myapp$ rails generate scaffold environment
> description:string has_many:engines
>       invoke  active_record
>       create    db/migrate/20121226181441_create_environments.rb
>       create    app/models/environment.rb
>       invoke    test_unit
>       create      test/unit/environment_test.rb
>       create      test/fixtures/environments.yml
>       invoke  resource_route
>        route    resources :environments
>       invoke  scaffold_controller
>       create    app/controllers/environments_controller.rb
>       invoke    erb
>       create      app/views/environments
>       create      app/views/environments/index.html.erb
>       create      app/views/environments/edit.html.erb
>       create      app/views/environments/show.html.erb
>       create      app/views/environments/new.html.erb
>       create      app/views/environments/_form.html.erb
>       invoke    test_unit
>       create      test/functional/environments_controller_test.rb
>       invoke    helper
>       create      app/helpers/environments_helper.rb
>       invoke      test_unit
>       create        test/unit/helpers/environments_helper_test.rb
>       invoke  assets
>       invoke    coffee
>       create      app/assets/javascripts/environments.js.coffee
>       invoke    scss
>       create      app/assets/stylesheets/environments.css.scss
>       invoke  scss
>    identical    app/assets/stylesheets/scaffolds.css.scss
> user@user-user:~/dev/myapp$ rails generate scaffold state
> description:string has_many:engines
>       invoke  active_record
>       create    db/migrate/20121226181504_create_states.rb
>       create    app/models/state.rb
>       invoke    test_unit
>       create      test/unit/state_test.rb
>       create      test/fixtures/states.yml
>       invoke  resource_route
>        route    resources :states
>       invoke  scaffold_controller
>       create    app/controllers/states_controller.rb
>       invoke    erb
>       create      app/views/states
>       create      app/views/states/index.html.erb
>       create      app/views/states/edit.html.erb
>       create      app/views/states/show.html.erb
>       create      app/views/states/new.html.erb
>       create      app/views/states/_form.html.erb
>       invoke    test_unit
>       create      test/functional/states_controller_test.rb
>       invoke    helper
>       create      app/helpers/states_helper.rb
>       invoke      test_unit
>       create        test/unit/helpers/states_helper_test.rb
>       invoke  assets
>       invoke    coffee
>       create      app/assets/javascripts/states.js.coffee
>       invoke    scss
>       create      app/assets/stylesheets/states.css.scss
>       invoke  scss
>    identical    app/assets/stylesheets/scaffolds.css.scss
> user@user-user:~/dev/myapp$ rake db:create
> user@user-user:~/dev/myapp$ rake db:migrate
> ==  CreateEngines: migrating
> =================================================> --
create_table(:engines)
> rake aborted!
> An error has occurred, this and all later migrations canceled:
>
> undefined method `environment'' for
> #<ActiveRecord::ConnectionAdapters::TableDefinition:0x00000001ca2ff0>
> /home/user/temp/project/db/migrate/20121226181404_create_engines.rb:4:in
> `block in change''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/connection_adapters/abstract/schema_statements.rb:160:in
> `create_table''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:466:in
> `block in method_missing''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:438:in
> `block in say_with_time''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:438:in
> `say_with_time''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:458:in
> `method_missing''
> /home/user/temp/project/db/migrate/20121226181404_create_engines.rb:3:in
> `change''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:407:in
> `block (2 levels) in migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:407:in
> `block in migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/connection_adapters/abstract/connection_pool.rb:129:in
> `with_connection''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:389:in
> `migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:528:in
> `migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:720:in
> `block (2 levels) in migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:775:in
> `call''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:775:in
> `block in ddl_transaction''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/connection_adapters/abstract/database_statements.rb:192:in
> `transaction''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/transactions.rb:208:in
> `transaction''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:775:in
> `ddl_transaction''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:719:in
> `block in migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:700:in
> `each''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:700:in
> `migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:570:in
> `up''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/migration.rb:551:in
> `migrate''
> /home/user/.rvm/gems/ruby-1.9.3-p327/gems/activerecord-3.2.9/lib/active_rec
ord/railties/databases.rake:179:in
> `block (2 levels) in <top (required)>''
> /home/user/.rvm/gems/ruby-1.9.3-p327/bin/ruby_noexec_wrapper:14:in
`eval''
> /home/user/.rvm/gems/ruby-1.9.3-p327/bin/ruby_noexec_wrapper:14:in
`<main>''
> Tasks: TOP => db:migrate
> (See full trace by running task with --trace)
>
>
>
>
>
>
>
> On Wednesday, December 26, 2012 8:27:27 AM UTC-5, Frederick Cheung wrote:
>
> > On Dec 26, 2:25 am, Julien Estebane
<julienesteb...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > > Hello,
>
> > > I am having what I might think is a basic problem...I
can''t get the
> > > relationships of has_many and belongs_to mapped out correctly in
the
> > > database. I would expect, according to my MODEL and MIGRATION,
that
> > there
> > > would be a desktop_id in the states and environments DATABASE
table ?
>
> > > How can I get the desktop_id, state_id and environment_id columns
mapped
> > > out in the tables ?
>
> > There need to be statements in your migrations to add those columns -
> > rails won''t look at the models and work it out from the
associations
> > in there.
>
> > You may be confusing things with datamapper (that does do this I
> > think) or with the fact that if you do rails g model foo
> > belongs_to:bar then rails will add the belongs_to to the model and the
> > migration.
>
> > Fred.
>
> > > I ran rake db:migrate before going to the rails console and
checking the
> > > tables...
>
> > > MODEL:
> > > ------
>
> > > user@user-DevMachine:~/dev/myapp/app/models$ cat engine.rb
> > > class Engine < ActiveRecord::Base
> > >   # attr_accessible :title, :body
> > >   belongs_to :environment
> > >   belongs_to :state
> > > end
> > > user@user-DevMachine:~/dev/myapp/app/models$ cat environment.rb
> > > class Environment < ActiveRecord::Base
> > >   attr_accessible :description
> > >   has_many :engines
> > > end
> > > user@user-DevMachine:~/dev/myapp/app/models$ cat state.rb
> > > class State < ActiveRecord::Base
> > >   attr_accessible :description
> > >   has_many :engines
> > > end
>
> > > MIGRATION:
> > > ----------
>
> > > user@user-DevMachine:~/dev/myapp/db/migrate$ cat
> > > 20121225230016_create_engines.rb
> > > class CreateEngines < ActiveRecord::Migration
> > >   def change
> > >     create_table :engines do |t|
>
> > >       t.timestamps
> > >     end
> > >   end
> > > end
> > > user@user-DevMachine:~/dev/myapp/db/migrate$ cat
> > > 20121225230034_create_states.rb
> > > class CreateStates < ActiveRecord::Migration
> > >   def change
> > >     create_table :states do |t|
> > >       t.string :description
>
> > >       t.timestamps
> > >     end
> > >   end
> > > end
> > > user@user-DevMachine:~/dev/myapp/db/migrate$ cat
> > > 20121225230118_create_environments.rb
> > > class CreateEnvironments < ActiveRecord::Migration
>
> ...
>
> read more »
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Julien Estebane

2012-Dec-27 00:01 UTC

head link

Re: has_to and belongs_to realtionships are not showing up in database

upon further investigation and a lot of googling, i have found that in 
order to get environment_id and state_id columns into the engines table, I 
have to add 

t.belongs_to :environment
t.belongs_to :state

into the migrations files.

Thanks for the assistance Frederic. :)

On Tuesday, December 25, 2012 9:25:17 PM UTC-5, Julien Estebane
wrote:>
> Hello,
>
> I am having what I might think is a basic problem...I can''t get
the
> relationships of has_many and belongs_to mapped out correctly in the 
> database. I would expect, according to my MODEL and MIGRATION, that there 
> would be a desktop_id in the states and environments DATABASE table ?
>
> How can I get the desktop_id, state_id and environment_id columns mapped 
> out in the tables ?
>
> I ran rake db:migrate before going to the rails console and checking the 
> tables...
>
> MODEL:
> ------
>
> user@user-DevMachine:~/dev/myapp/app/models$ cat engine.rb 
> class Engine < ActiveRecord::Base
>   # attr_accessible :title, :body
>   belongs_to :environment
>   belongs_to :state
> end
> user@user-DevMachine:~/dev/myapp/app/models$ cat environment.rb 
> class Environment < ActiveRecord::Base
>   attr_accessible :description
>   has_many :engines
> end
> user@user-DevMachine:~/dev/myapp/app/models$ cat state.rb 
> class State < ActiveRecord::Base
>   attr_accessible :description
>   has_many :engines
> end
>
>
>
> MIGRATION:
> ----------
>
> user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
> 20121225230016_create_engines.rb
> class CreateEngines < ActiveRecord::Migration
>   def change
>     create_table :engines do |t|
>
>       t.timestamps
>     end
>   end
> end
> user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
> 20121225230034_create_states.rb
> class CreateStates < ActiveRecord::Migration
>   def change
>     create_table :states do |t|
>       t.string :description
>
>       t.timestamps
>     end
>   end
> end
> user@user-DevMachine:~/dev/myapp/db/migrate$ cat 
> 20121225230118_create_environments.rb
> class CreateEnvironments < ActiveRecord::Migration
>   def change
>     create_table :environments do |t|
>       t.string :description
>       t.timestamps
>     end
>   end
> end
> user@user-DevMachine:~/dev/myapp/db/migrate$ 
>
>
>
> DATABASE:
> ---------
>
> user@user-DevMachine:~/dev/myapp/db/migrate$ rails console
> Loading development environment (Rails 3.2.9)
> 1.9.3-p327 :001 > ActiveRecord::Base.connection.execute("SELECT *
FROM
> engines")
>    (1.1ms)  SELECT * FROM engines
>  => [{"id"=>1, "created_at"=>"2012-12-26
01:26:38.789476",
> "updated_at"=>"2012-12-26 01:26:38.789476", 0=>1,
1=>"2012-12-26
> 01:26:38.789476", 2=>"2012-12-26 01:26:38.789476"}] 
> 1.9.3-p327 :002 > ActiveRecord::Base.connection.execute("SELECT *
FROM
> environments")
>    (0.3ms)  SELECT * FROM environments
>  => [{"id"=>1,
"description"=>"warm",
"created_at"=>"2012-12-26
> 01:27:40.968920", "updated_at"=>"2012-12-26
01:27:40.968920", 0=>1,
> 1=>"warm", 2=>"2012-12-26 01:27:40.968920",
3=>"2012-12-26
> 01:27:40.968920"}, {"id"=>2,
"description"=>"cold",
> "created_at"=>"2012-12-26 01:27:41.055711",
"updated_at"=>"2012-12-26
> 01:27:41.055711", 0=>2, 1=>"cold",
2=>"2012-12-26 01:27:41.055711",
> 3=>"2012-12-26 01:27:41.055711"}, {"id"=>3,
"description"=>"hot",
> "created_at"=>"2012-12-26 01:27:41.129397",
"updated_at"=>"2012-12-26
> 01:27:41.129397", 0=>3, 1=>"hot",
2=>"2012-12-26 01:27:41.129397",
> 3=>"2012-12-26 01:27:41.129397"}, {"id"=>4,
"description"=>"freezing",
> "created_at"=>"2012-12-26 01:27:41.284936",
"updated_at"=>"2012-12-26
> 01:27:41.284936", 0=>4, 1=>"freezing",
2=>"2012-12-26 01:27:41.284936",
> 3=>"2012-12-26 01:27:41.284936"}] 
> 1.9.3-p327 :003 > ActiveRecord::Base.connection.execute("SELECT *
FROM
> states")
>    (0.4ms)  SELECT * FROM states
>  => [{"id"=>1,
"description"=>"running",
"created_at"=>"2012-12-26
> 01:27:40.452140", "updated_at"=>"2012-12-26
01:27:40.452140", 0=>1,
> 1=>"running", 2=>"2012-12-26 01:27:40.452140",
3=>"2012-12-26
> 01:27:40.452140"}, {"id"=>2,
"description"=>"stopping",
> "created_at"=>"2012-12-26 01:27:40.536188",
"updated_at"=>"2012-12-26
> 01:27:40.536188", 0=>2, 1=>"stopping",
2=>"2012-12-26 01:27:40.536188",
> 3=>"2012-12-26 01:27:40.536188"}, {"id"=>3,
"description"=>"restarting",
> "created_at"=>"2012-12-26 01:27:40.613507",
"updated_at"=>"2012-12-26
> 01:27:40.613507", 0=>3, 1=>"restarting",
2=>"2012-12-26 01:27:40.613507",
> 3=>"2012-12-26 01:27:40.613507"}, {"id"=>4,
"description"=>"creating",
> "created_at"=>"2012-12-26 01:27:40.688855",
"updated_at"=>"2012-12-26
> 01:27:40.688855", 0=>4, 1=>"creating",
2=>"2012-12-26 01:27:40.688855",
> 3=>"2012-12-26 01:27:40.688855"}, {"id"=>5,
"description"=>"destroying",
> "created_at"=>"2012-12-26 01:27:40.768293",
"updated_at"=>"2012-12-26
> 01:27:40.768293", 0=>5, 1=>"destroying",
2=>"2012-12-26 01:27:40.768293",
> 3=>"2012-12-26 01:27:40.768293"}] 
> 1.9.3-p327 :004 > 
>
>
> Thanks 
>
> Julien Estebane
>
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Rails - Dec 2012 - has_to and belongs_to realtionships are not showing up in database

has_to and belongs_to realtionships are not showing up in database

Re: has_to and belongs_to realtionships are not showing up in database

Re: has_to and belongs_to realtionships are not showing up in database

Re: has_to and belongs_to realtionships are not showing up in database

Re: has_to and belongs_to realtionships are not showing up in database