uninitialized constant when trying to migrate files

rubyonrails-talk
1

Hi,

i am having this problem:

kevinngsw$ rake db:migrate --trace (in /Users/kevinngsw/Documents/Programming/*******) ** Invoke db:migrate (first_time) ** Invoke environment (first_time) ** Execute environment ** Execute db:migrate rake aborted! An error has occurred, this and all later migrations canceled:

uninitialized constant CreateUrls /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:443:in `load_missing_constant' /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:80:in `const_missing' /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:92:in `const_missing' /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/inflector.rb:361:in `constantize' /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/inflector.rb:360:in `each' /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/inflector.rb:360:in `constantize' /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/string/inflections.rb:162:in `constantize' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:374:in `load_migration' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:369:in `migration' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:365:in `migrate' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:486:in `migrate' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:560:in `call' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:560:in `ddl_transaction' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/database_statements.rb:136:in `transaction' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/transactions.rb:182:in `transaction' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:560:in `ddl_transaction' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:485:in `migrate' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:472:in `each' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:472:in `migrate' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:400:in `up' /usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/migration.rb:383:in `migrate' /usr/local/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/tasks/databases.rake:116 /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain' /usr/local/lib/ruby/1.8/monitor.rb:242:in `synchronize' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run' /usr/local/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31 /usr/local/bin/rake:19:in `load' /usr/local/bin/rake:19

this is the migration file:

class CreateURLs < ActiveRecord::Migration   def self.up     create_table :urls do |t|       t.string :label       t.string :url

      t.timestamps     end   end

  def self.down     drop_table :urls   end end

this is the model file:

class URL < ActiveRecord::Base   belongs_to :contact_person end

any help is appreciated. Thanks!!

2

whats the name of your file? looking at the class it should be named *_create_u_r_ls.rb. if it is called *_create_urls.rb then your class should be CreateUrls. smae with your model. try Url instead of URL.

3

Assuming the file is some_number_create_urls.rb Rails is expecting the migration class to be CreateUrls (similarly rails will expect to find a model class called Url in url.rb)

Fred