我有一个 Article 模型，它可以有许多不同类型的内容块。所以一个 Article 可以有很多 HeadingBlocks 和 ParagraphBlocks 像这样：
class Article < ApplicationRecord
has_many :heading_blocks
has_many :paragraph_blocks
end
class HeadingBlock < ApplicationRecord
belongs_to :article
end
class ParagraphBlock < ApplicationRecord
belongs_to :article
end我希望能够使用相同的名称 (blocks) 为 HeadingBlock 和 ParagraphBlock 起别名，因此如果我有一篇文章的实例，我可以执行以下操作：
@article.blocks // returns all heading blocks and paragraph blocks associated这在 Rails 中可行吗？如果是这样，您能否提供一个示例，说明如何使用相同名称为多个关联中的多个模型起别名？
谢谢你。
回答1
您可以有一个返回块数组的方法：
class Article < ApplicationRecord
has_many :heading_blocks
has_many :paragraph_blocks
# NOTE: returns an array of heading and paragraph blocks
def blocks
heading_blocks + paragraph_blocks
end
end您可以重新组织关系以具有多态关联：
class Article < ApplicationRecord
has_many :blocks
end
# NOTE: to add polymorphic relationship add this in your migration:
# t.references :blockable, polymorphic: true
class Block < ApplicationRecord
belongs_to :article
belongs_to :blockable, polymorphic: true
end
class HeadingBlock < ApplicationRecord
has_one :block, as: :blockable
end
class ParagraphBlock < ApplicationRecord
has_one :block, as: :blockable
end如果可以将 HeadingBlock 和 ParagraphBlock 合并到一个数据库 table 中：
class Article < ApplicationRecord
has_many :blocks
end
# id
# article_id
# type
class Block < ApplicationRecord
belongs_to :article
# set type as needed to `:headding` or `:paragraph`
end
# NOTE: I'd avoid STI; but this does set `type` column automatically to `ParagraphBlock`
# class ParagraphBlock < Block
# end