我正在使用Dr.Nic的复合主键(http://compositekeys.
rubyforge.org/)
在示例中,他有has_many和belongs_to关系,但没有has_and_belongs_to_many
我的协会在书籍和流派之间运作良好(书籍具有标题和作者的复合素数键),但是书籍的类型试图查询连接表中不存在的列book_id,并引发错误.
class Book < ActiveRecord::Base self.primary_keys = :title,:author has_and_belongs_to_many :genres,foreign_key: [:title,:author] end class Genre < ActiveRecord::Base has_and_belongs_to_many :books,:author] end
编辑：我也使用它来工作：类型模型上的association_foreign_key选项
class Genre < ActiveRecord::Base has_and_belongs_to_many :books,association_foreign_key: [:title,:author] end
解决方法
根据
Ruby on Rails Style Guide：
Prefer has_many :through to has_and_belongs_to_many. Using has_many :through allows additional attributes and validations on the join model.
这将解决您的问题：您将只有has_many和belongs_to关系,没有HABTM;)
在你的情况下：
class Book < ActiveRecord::Base self.primary_keys = :title,:author has_many :book_genre_relations has_many :genres,through: :book_genre_relations end class Genre < ActiveRecord::Base has_many :book_genre_relations has_many :books,through: :book_genre_relations end class BookGenreRelation < ActiveRecord::Base # Sorry but couldn't find a better name... belongs_to :book belongs_to :genre end
您可能必须更改foreign_key的拼写错误,我不熟悉复合主键.