调用带有enum_attr的记录时.all的参数数量错误

Question

MODEL1有一个account_type,所以使用gem'enumerated_attributes',我做了这样的模型:

class MODEL1 < ActiveRecord::Base

  enum_attr :account_type, %w(^live demo disabled)

  def is_live?
    self.account_type == :live
  end
  def is_not_live?
    self.account_type == :demo || self.account_type == :disabled
  end
end

我不明白的奇怪之处在于,当我查询任意MODEL1这样的种子时(这是我在rubymine控制台中运行follwing命令时的错误,但是在rake db:seed期间发生同样的2 for 1错误) :

MODEL1.all.sample

和

MODEL1.all

我明白了:

Dealer Load (0.3ms)  SELECT "MODEL1".* FROM "MODEL1S"
ArgumentError: wrong number of arguments (2 for 1)
from /.rvm/gems/ruby-2.0.0-p0@web/gems/enumerated_attribute-0.2.16/lib/enumerated_attribute/integrations/active_record.rb:78:in `instantiate'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/querying.rb:45:in `block in find_by_sql'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/result.rb:21:in `block in each'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/result.rb:21:in `each'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/result.rb:21:in `each'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/querying.rb:45:in `map'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/querying.rb:45:in `find_by_sql'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/relation.rb:585:in `exec_queries'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/relation.rb:471:in `load'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/relation.rb:220:in `to_a'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/activerecord-4.0.0/lib/active_record/relation/delegation.rb:49:in `sample'
from (irb):7
from /.rvm/gems/ruby-2.0.0-p0@web/gems/railties-4.0.0/lib/rails/commands/console.rb:90:in `start'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/railties-4.0.0/lib/rails/commands/console.rb:9:in `start'
from /.rvm/gems/ruby-2.0.0-p0@web/gems/railties-4.0.0/lib/rails/commands.rb:64:in `<top (required)>'

我试图播种的模型(在rake db:seed期间发生错误的地方)是这样的:

  model2 = Fabricate(:MODEL2, name: "Any MODEL2 Name #{n}", cost: n, MODEL1: MODEL1.all.sample)

在MODEL2模型中

belongs_to :MODEL1

在MODEL1模型中

has_many :MODEL2s

在迁移中,MODEL2

t.references :MODEL1

在迁移中,MODEL1

t.enum :account_type

如果有更简单的方法为MODEL1指定account_types,请告诉我,我只需要能够说出MODEL1.all.sample或MODEL1.all

Answer 1

看来您正在使用 Rails 4，从发行说明来看：

Model.all 现在返回 ActiveRecord::Relation，而不是记录数组。如果您确实想要一个数组，请使用 Relation#to_a。在某些特定情况下，这可能会导致升级时损坏。

因此，对于初学者来说，您需要调用to_a该模型。但是你确定 enumerated_attribute 已经准备好 Rails 4 了吗？

如果您不使用 postres，我建议仅使用 validates_inclusion_of，如果您使用 postgres，请查看https://coderwall.com/p/azi3ka