CODEWITHSUNDEEP
ruby-on-rails
Metaphysiker
Metaphysiker

Reputation: 1093

Rails, Uninitialized constant after rake db:migrate

I'm following the book: "Rails, Angular, Postgres and Bootstrap". At some point, the author wrote a new migration, with this code:

class AddAddresses < ActiveRecord::Migration
  def change
    create_table :states do |t|
      t.string :code, size: 2, null: false
      t.string :name,          null: false
    end

    create_table :addresses do |t|
      t.string     :street,                    null: false
      t.string     :city,                      null: false
      t.references :state,                     null: false
      t.string     :zipcode,                   null: false
    end

    create_table :customers_billing_addresses do |t|
      t.references :customer, null: false
      t.references :address,  null: false
    end

    create_table :customers_shipping_addresses do |t|
      t.references :customer, null: false
      t.references :address,  null: false
      t.boolean :primary, null: false, default: false
    end
  end
end

Here is what I did:

  1. rails g migration add-addresses

  2. Copied and pasted the code above in the generated migration-file

  3. rake db:migrate

This happens:

== 20161211174928 AddAddresses: migrating =====================================
-- create_table(:states)
   -> 0.0140s
-- create_table(:addresses)
   -> 0.0129s
-- create_table(:customers_billing_addresses)
   -> 0.0115s
-- create_table(:customers_shipping_addresses)
   -> 0.0142s
== 20161211174928 AddAddresses: migrated (0.0529s) ============================
  1. rails c

  2. State.last causes this:

    NameError: uninitialized constant State

  3. I checked, whether 'State' was around: 

    ActiveRecord::Base.connection.tables.map do |model|  
  model.capitalize.singularize.camelize
end

leads to:

["SchemaMigration", "ArInternalMetadatum", "User", "Customer", "State", "Address", "CustomersBillingAddress", "CustomersShippingAddress"]

Since 'State' is clearly there, I'm clueless what the problem is. Any suggestions?

PS: I already tried this, but the problem remains:

rake db:drop:all
rake db:create:all
rake db:migrate

Upvotes: 1

Views: 2770

Answers (2)

Tom Connolly
Tom Connolly

Reputation: 694

Since you indicate State.code and State.name cannot be blank, and very likely do not have any data in the table, start by creating some data, i.e.:

state = State.create(code: 12, name: "New Jersey")

Make a file called state.rb in the models directory. in it put:

class State < ActiveRecord::Base
end

and see if that works. Later you can add the associations. This will initialize the class.

Upvotes: 0

Arun Kumar Mohan
Arun Kumar Mohan

Reputation: 11915

Do you have a state.rb file under app/models directory? I guess you don't. Creating a table will not generate the model(class) while generating the model using rails g model will create the migration for you.

Create a file called state.rb in app/models and add the following contents to the file.

class State < ActiveRecord::Base
end

Upvotes: 2

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