NoMethodError: неопределенный метод `value_for_database'для #<Array> (Rails 5)

Question

У меня есть (совершенно новый) проект Rails 5, который выдает ошибки при попытке запустить миграцию.

(Я запускаю Ruby 2.2.4 на Raspberry Pi с использованием PostgreSQL 9.4, но то же сообщение об ошибке выскочило, когда я впервые попробовал запустить миграцию с SQLite.)

Пока единственная миграция, которую я получил, довольно проста:

class CreateAuthors < ActiveRecord::Migration[5.0]
  def change
    create_table :authors do |t|
      t.string :username
      t.timestamps
    end
  end
end

Это приводит к следующему выводу при запуске rake db:migrate,

pi@raspberrypi:~/projects/gnn $ rake db:migrate
== 20160915091621 CreateAuthors: migrating ====================================
-- create_table(:authors, {})
   -> 0.0283s
== 20160915091621 CreateAuthors: migrated (0.0287s) ===========================

rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

undefined method `value_for_database' for #<Array:0x2a10470>
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `block in exec_no_cache'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `each'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `map'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `exec_no_cache'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:587:in `execute_and_clear'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:103:in `exec_query'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:135:in `exec_insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:124:in `insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:65:in `insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:554:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/counter_cache.rb:128:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/locking/optimistic.rb:75:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/attribute_methods/dirty.rb:123:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:302:in `block in _create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:97:in `__run_callbacks__'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:750:in `_run_create_callbacks'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:302:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/timestamp.rb:68:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:534:in `create_or_update'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:298:in `block in create_or_update'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:97:in `__run_callbacks__'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:750:in `_run_save_callbacks'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:298:in `create_or_update'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:152:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/validations.rb:50:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/attribute_methods/dirty.rb:30:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:324:in `block in save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:395:in `block in with_transaction_returning_status'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:230:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:211:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:392:in `with_transaction_returning_status'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:324:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/suppressor.rb:45:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:51:in `create!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1247:in `record_version_state_after_migrating'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1212:in `block in execute_migration_in_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1279:in `block in ddl_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `block in transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/transaction.rb:189:in `within_new_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:211:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1279:in `ddl_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1210:in `execute_migration_in_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1183:in `block in migrate_without_lock'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1182:in `each'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1182:in `migrate_without_lock'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1131:in `block in migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1298:in `with_advisory_lock'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1131:in `migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1005:in `up'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:983:in `migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/tasks/database_tasks.rb:161:in `migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/railties/databases.rake:58:in `block (2 levels) in <top (required)>'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/rake-11.2.2/exe/rake:27:in `<top (required)>'
NoMethodError: undefined method `value_for_database' for #<Array:0x2a10470>
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `block in exec_no_cache'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `each'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `map'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:597:in `exec_no_cache'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:587:in `execute_and_clear'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:103:in `exec_query'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:135:in `exec_insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:124:in `insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:65:in `insert'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:554:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/counter_cache.rb:128:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/locking/optimistic.rb:75:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/attribute_methods/dirty.rb:123:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:302:in `block in _create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:97:in `__run_callbacks__'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:750:in `_run_create_callbacks'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:302:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/timestamp.rb:68:in `_create_record'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:534:in `create_or_update'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:298:in `block in create_or_update'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:97:in `__run_callbacks__'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:750:in `_run_save_callbacks'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/callbacks.rb:298:in `create_or_update'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:152:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/validations.rb:50:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/attribute_methods/dirty.rb:30:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:324:in `block in save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:395:in `block in with_transaction_returning_status'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:230:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:211:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:392:in `with_transaction_returning_status'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:324:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/suppressor.rb:45:in `save!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/persistence.rb:51:in `create!'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1247:in `record_version_state_after_migrating'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1212:in `block in execute_migration_in_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1279:in `block in ddl_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `block in transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/transaction.rb:189:in `within_new_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/transactions.rb:211:in `transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1279:in `ddl_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1210:in `execute_migration_in_transaction'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1183:in `block in migrate_without_lock'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1182:in `each'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1182:in `migrate_without_lock'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1131:in `block in migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1298:in `with_advisory_lock'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1131:in `migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:1005:in `up'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/migration.rb:983:in `migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/tasks/database_tasks.rb:161:in `migrate'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/activerecord-5.0.0.1/lib/active_record/railties/databases.rake:58:in `block (2 levels) in <top (required)>'
/home/pi/.rvm/gems/ruby-2.2.4@gnn/gems/rake-11.2.2/exe/rake:27:in `<top (required)>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

Редактировать: Может быть, стоит сказать, что rake db:create бежал нормально.

Вот мой database.yml файл, на случай, если я что-то там упустил (я довольно зеленый с PostgreSQL)

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  database: gnn_dev
  username: gnn
  password: Lorem123
  host: localhost
  port: 5432

Answer 1

Я встречал ту же проблему в середине разработки. Нашли причину.

В моем случае я добавил новый гем 'imgurapi', который добавляет 'to_hash' к объектам Array

class Array # :nodoc:
  # Skipped code 

  def to_hash # :nodoc:
    inject({}) { |hsh, (k,v)| hsh[k] = v  ; hsh }
  end unless method_defined?(:to_hash)
end

Как результат вызывающий код exec_query(sql, name, binds) в gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:135:in 'exec_insert' новообращенные binds переменная из массива в тип хэша по причине, это хорошо описано здесь https://makandracards.com/makandra/36013-heads-up-ruby-implicitly-converts-a-hash-to-keyword-arguments. В результате мы имеем ошибку, потому что это преобразование является неожиданным.

Решение

Найдите гем, который определяет метод to_hash для Array, и избавьтесь от этого определения. Удачи!

Answer 2

Удалите [5.0] из первой строки.

class CreateAuthors < ActiveRecord::Migration 
  def change
    create_table :authors do |t|
      t.string :username
      t.timestamps
    end
  end
end

Спасибо

Answer 3

Удалить [5.0] из первой строки

Перезагрузите сервер и запустите rake db:migrate.

Может быть, это поможет вам.