列のタイプを変更しようとしていますが、エラーが発生します。私のモデルはConfで、列名はxmlです。:fileからに変更したいです:binary。xml最初は として作成されていましたが、このような移行ファイルにtext変更しました。file同じことをもう一度やりたいのですが、タイプをに変更しbinaryますが、エラーが発生します。
移行ファイルがあります：
class ChangeConfXmlColumnToBinary < ActiveRecord::Migration
def up
change_column :confs, :xml, :binary
end
def down
change_column :confs, :xml, :file
end
end
これはエラーです：
== ChangeConfXmlColumnToBinary: migrating ====================================
-- change_column(:confs, :xml, :binary)
rake aborted!
An error has occurred, this and all later migrations canceled:
undefined method `to_sym' for nil:NilClass/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/schema_definitions.rb:229:in `column'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:506:in `block (2 levels) in copy_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:500:in `each'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:500:in `block in copy_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/schema_statements.rb:160:in `create_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:498:in `copy_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:488:in `move_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:481:in `block in alter_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:480:in `alter_table'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/sqlite_adapter.rb:441:in `change_column'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:466:in `block in method_missing'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:438:in `block in say_with_time'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:438:in `say_with_time'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:458:in `method_missing'
/home/staj/rails_projects/sample_app/db/migrate/20130826113731_change_conf_xml_column_to_binary.rb:3:in `up'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:410:in `block (2 levels) in migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:410:in `block in migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:129:in `with_connection'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:389:in `migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:528:in `migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:720:in `block (2 levels) in migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:775:in `call'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:775:in `block in ddl_transaction'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/transactions.rb:208:in `transaction'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:775:in `ddl_transaction'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:719:in `block in migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:700:in `each'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:700:in `migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:570:in `up'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/migration.rb:551:in `migrate'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/gems/activerecord-3.2.13/lib/active_record/railties/databases.rake:193:in `block (2 levels) in <top (required)>'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/bin/ruby_noexec_wrapper:14:in `eval'
/home/staj/.rvm/gems/ruby-1.9.3-p429@rails3tutorial2ndEd/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
rake db:rollback-- change_column(:confs, :xml, :text)先頭に " " がある同じエラーを返します