收到ActiveRecord的关系，但需要对象

Question

我写了下面的类：

class Occupation < ActiveRecord::Base 
    has_many :pref_labels 
    has_many :cv_occupations 
    has_many :cvs, :through => :cv_occupations 
    validates_uniqueness_of :uri 

    # This function will return the specified label for the given language. 
    def label(language = Language.find_or_create_by_code(:en)) 
    self.pref_labels.where("language_id = #{language.id}") 
    end 
end 

class PrefLabel < ActiveRecord::Base 
    belongs_to :language 
    belongs_to :concept 
    belongs_to :skill 
    belongs_to :occupation 
    validates_uniqueness_of :value, :scope => [:language_id, :value] 
    validates_uniqueness_of :language_id, :scope => [:language_id, :value] 
end 

在我看来，我把以下内容：％TD = occupation.label（@language） 但这种回报作为错误：

undefined method `value' for #<ActiveRecord::Relation:0x80c8368> 

我怎样才能得到真正的对象返回而不是关系？我知道这事做与延迟加载....

Answer 1

变化

self.pref_labels.where("language_id = #{language.id}") 

要

self.pref_labels.where("language_id = #{language.id}").all #or .first if you only one the first one