title: unable to execute the rake:db command successfully
body: <p>I am facing this error while doing the rake db:migrate part. I am following the Michael Hartl tutorial and I seem lost at this point and have been trying out a lot of solutions available online but they don't seem to be too much of a help. I am not sure how to solve this problem. I am a total newbie. Am I doing something wrong? Can you point out where? BTW this is the first model I am creating.</p>
  
  <pre><code>bundle exec rake db:migrate 
  DEPRECATION WARNING: config.whiny_nils option is deprecated and no longer works. (called from block in &lt;top (required)&gt; at /home/aravind/coderor/demo_app1/config/environments/development.rb:10)
  DEPRECATION WARNING: Model based mass assignment security has been extracted out of Rails into a gem. Please use the new recommended protection model for params or add `protected_attributes` to your Gemfile to use the old one.
  
  To disable this message remove the `whitelist_attributes` option from your
  `config/application.rb` file and any `mass_assignment_sanitizer` options
  from your `config/environments/*.rb` files.
  
  See http://guides.rubyonrails.org/security.html#mass-assignment for more information.
  
  DEPRECATION WARNING: The Active Record auto explain feature has been removed.
  
  To disable this message remove the `active_record.auto_explain_threshold_in_seconds`
  option from the `config/environments/*.rb` config file.
  
  See http://guides.rubyonrails.org/4_0_release_notes.html for more information.
  
  ==  CreateUsers: migrating ====================================================
  -- create_table(:users)
  rake aborted!
  An error has occurred, this and all later migrations canceled:
  
  private method `String' called for         #&lt;ActiveRecord::ConnectionAdapters::TableDefinition:0x00000004606298&gt;/home/aravind    /coderor    /demo_app1/db/migrate/20130628051457_create_users.rb:4:in `block in change'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/schema_statements.rb:184:in `create_table'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:625:in `block in method_missing'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:597:in `block in say_with_time'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:597:in `say_with_time'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:617:in `method_missing'
  /home/aravind/coderor/demo_app1/db/migrate/20130628051457_create_users.rb:3:in `change'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:571:in `exec_migration'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:555:in `block (2 levels) in migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:554:in `block in migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:294:in `with_connection'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:553:in `migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:709:in `migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:959:in `block in execute_migration_in_transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:1005:in `block in ddl_transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `block in transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:210:in `within_new_transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract    /database_statements.rb:202:in `transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in `transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:1005:in `ddl_transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:958:in `execute_migration_in_transaction'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:920:in `block in migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:916:in `each'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:916:in `migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:764:in `up'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/migration.rb:742:in `migrate'
  /var/lib/gems/1.9.1/gems/activerecord-4.0.0/lib/active_record/railties    /databases.rake:42:in `block (2 levels) in &lt;top (required)&gt;'
  Tasks: TOP =&gt; db:migrate
  (See full trace by running task with --trace)
  </code></pre>
  
  <p>Here is the migration file</p>
  
  <pre><code>class CreateUsers &lt; ActiveRecord::Migration
  def change
  create_table :users do |t|
  t.String :name
  t.String :email
  t.timestamps
  end
  end
  end
  </code></pre>