我正在使用 rails 3.2.8 并且在多态关联方面遇到了一些麻烦。我有一个模型活动,它是多态的,它与另一个多态模型贡献相关,可以是资产文件、传记、动态注释或引用。
所以祖父是活动......父亲是贡献,最后(贡献的)儿子是传记,资产文件,动态注释或引文。
我的模型东西聚合了所有这些概念,我有下一个代码:
has_many :activities,
:order => 'created_at DESC',
:dependent =>:delete_all
has_many :contributions,
:through => :activities,
:source => :activable,
:source_type => "Contribution"
has_many :dynamic_annotations,
:through => :contributions,
:source => :contributable,
:source_type => "DynamicAnnotation",
:conditions => {"contributions.c_state" => "ACCEPTED"}
has_many :biographies,
:through => :contributions,
:source => :contributable,
:source_type => "Biography",
:conditions => {"contributions.c_state" => "ACCEPTED"}
has_many :citations,
:through => :contributions,
:source => :contributable,
:source_type => "Citation",
:conditions => {"contributions.c_state" => "ACCEPTED"}
has_many :asset_files,
:through => :contributions,
:source => :contributable,
:source_type => "AssetFile",
:conditions => {"contributions.c_state" => "ACCEPTED"}
问题:我打开控制台并输入了下一个查询:
Thing.first.biographies
我得到的sql:
SELECT `biographies`.* FROM `biographies` INNER JOIN `contributions` ON `biographies`.`id` = `contributions`.`contributable_id` INNER JOIN `activities` ON `contributions`.`id` = `activities`.`activable_id` WHERE `activities`.`thing_id` = 1 AND `activities`.`activable_type` = 'Contribution' AND (`contributions`.`c_state` = 'ACCEPTED') AND (`contributions`.`contributable_type` = 'Biography')
这是一个正确的答案
然后我在命令后输入:
Thing.first.dynamic_annotations
我得到的sql:
SELECT `dynamic_annotations`.* FROM `dynamic_annotations` INNER JOIN `contributions` ON `dynamic_annotations`.`id` = `contributions`.`contributable_id` INNER JOIN `activities` ON `contributions`.`id` = `activities`.`activable_id` WHERE `activities`.`thing_id` = 1 AND `activities`.`activable_type` = 'Contribution' AND (`contributions`.`c_state` = 'ACCEPTED') AND (`contributions`.`contributable_type` = 'Biography' AND `contributions`.`contributable_type` = 'DynamicAnnotation')
我得到了一个 void 结果,因为该对象不能有两种类型的 corse。
如果有人可以帮助我,我会很感激:)
提前致谢,