Rails 迁移不会在 prod 中运行

Question

我正在使用 Rails 迁移转换一些数据：

class MigrateInstancesToFacets < ActiveRecord::Migration[5.1]
  def change
    say "Found #{Instance.where(rev: nil).count} records to migrate"

    say_with_time "Migrating instances..." do
      user = User.first
      count = 0
      Instance.find_each do |instance|
        CatalogFacet.create(
          photo: instance.photo,
          catalog: instance.catalog,
          user: user
        )
        instance.update(rev: true)
        count += 1
      end
      count
    end
    fail_count = Instance.where(rev: nil).count
    fail "Found #{fail_count} not migrated records" unless fail_count == 0
  end
end

我第一次在我的开发环境中运行它，一切都很顺利。 然后我在我的生产环境中运行它，但是失败了：

pi@pi0:~/pt_api $ RAILS_ENV="production" rake db:migrate
I, [2017-09-04T07:11:51.315838 #29058]  INFO -- : Migrating to MigrateInstancesToFacets (20170831110928)
== 20170831110928 MigrateInstancesToFacets: migrating =========================
-- Found 25671 records to migrate
-- Migrating instances...
rake aborted!
StandardError: An error has occurred, all later migrations canceled:

uninitialized constant Instance::Catalog
/home/pi/pt_api/db/migrate/20170831110928_migrate_instances_to_facets.rb:9:in `block (2 levels) in change'
/home/pi/pt_api/db/migrate/20170831110928_migrate_instances_to_facets.rb:8:in `block in change'
/home/pi/pt_api/db/migrate/20170831110928_migrate_instances_to_facets.rb:5:in `change'
NameError: uninitialized constant Instance::Catalog
/home/pi/pt_api/db/migrate/20170831110928_migrate_instances_to_facets.rb:9:in `block (2 levels) in change'
/home/pi/pt_api/db/migrate/20170831110928_migrate_instances_to_facets.rb:8:in `block in change'
/home/pi/pt_api/db/migrate/20170831110928_migrate_instances_to_facets.rb:5:in `change'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

这是说它无法访问实例上的目录。我打开了一个控制台并在那里运行相同的代码，一切都很好。 迁移时不加载环境吗？

---编辑--- 实例模型：

class Instance < ActiveRecord::Base
  belongs_to :catalog
  belongs_to :photo
  before_destroy :delete_photo

  def delete_photo
    catalog = Catalog.find self.catalog_id
    catalog.delete_photo(self.photo_id)
  end

end

Answer 1

您可以尝试更新迁移代码以使用_id 列创建它，而不是按原样传递实例

CatalogFacet.create(
  ...
  catalog_id: instance.catalog_id, 
  ...
)