rake 数据库迁移后未初始化的常量

Question

我想使用 rake db:migrate 添加一个名为 measurement_error_categories 的 table。

我用 bundle exec rake db:create_migration NAME=create_measurement_error_category_table 创建了一个迁移文件现在我在运行 bundle exec rake db:migrate

之后收到以下错误

== 20170620084816 CreateMeasurementErrorCategoryTable: migrating ==============
rake aborted!
An error has occurred, this and all later migrations canceled:

uninitialized constant CreateMeasurementErrorCategoryTable::MeasurementErrorCategory
/Users/ndinatale/leanlogic-qa-prototype/server/db/migrate/20170620084816_create_measurement_error_category_table.rb:3:in `change'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:602:in `exec_migration'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:586:in `block (2 levels) in migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:585:in `block in migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/connection_adapters/abstract/connection_pool.rb:294:in `with_connection'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:584:in `migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:759:in `migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:998:in `block in execute_migration_in_transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:1044:in `block in ddl_transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `block in transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/connection_adapters/abstract/database_statements.rb:209:in `within_new_transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/transactions.rb:208:in `transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:1044:in `ddl_transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:997:in `execute_migration_in_transaction'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:959:in `block in migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:955:in `each'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:955:in `migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:814:in `up'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/migration.rb:792:in `migrate'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.16/lib/active_record/railties/databases.rake:34:in `block (2 levels) in <top (required)>'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/cli/exec.rb:74:in `load'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/cli/exec.rb:74:in `kernel_load'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/cli/exec.rb:27:in `run'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/cli.rb:335:in `exec'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/vendor/thor/lib/thor.rb:359:in `dispatch'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/cli.rb:20:in `dispatch'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/vendor/thor/lib/thor/base.rb:440:in `start'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/cli.rb:11:in `start'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/exe/bundle:32:in `block in <top (required)>'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/lib/bundler/friendly_errors.rb:121:in `with_friendly_errors'
/Library/Ruby/Gems/2.0.0/gems/bundler-1.14.3/exe/bundle:24:in `<top (required)>'
/usr/local/bin/bundle:23:in `load'
/usr/local/bin/bundle:23:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

20170620084816_create_measurement_error_category_table.rb:

class CreateMeasurementErrorCategoryTable < ActiveRecord::Migration
  def change
    MeasurementErrorCategory.create_table(self, :measurementerrorcategories)
  end
end

measurement_error_category.rb:

class MeasurementErrorCategory < ActiveRecord::Base
  include ModelBase
  include Ordering

  # -----
  # Table setup
  # -----
  before_validation { complete_languageblock(false, :name) }

  validates :name, language: { complete: :all, minlength: 3 }

  # serialize json object (value) as newline delimited string in the database
  serialize :name

  augment_class_usertag

  def self.create_table(m,tn)
    m.create_table tn do |t|
      t.string :name
      t.integer :seqnum
      augment_table_usertag t
    end
  end
end

我做错了什么？

Answer 1

好的，我知道了。在 20170620084816_create_measurement_error_category_table.rb 我改变了

class CreateMeasurementErrorCategoryTable < ActiveRecord::Migration
  def change
    MeasurementErrorCategory.create_table(self, :measurementerrorcategories)
  end
end

到

class CreateMeasurementErrorCategoryTable < ActiveRecord::Migration
  def create
    MeasurementErrorCategory.create_table(self, :measurementerrorcategories)
  end
end

所以我将方法名称从 change 更改为 create。

rake 数据库迁移后未初始化的常量

Uninitialized constant after rake db migration

ruby-on-rails

activerecord

rake