自定义包括 rails 中的关联

Question

I have the following table

Users(user_id, name, last_name)

Relationships(user_id, spouse_id)

I want to run the following query

person = Relationships.includes(:person).where(:name => 'David')

But I don't want the related person to be associated by the user_id . I would rather it be associated by the spouse_id only for this specific query.

Answer 1

Rails is perfectly content to allow multiple associations to the same table, providing they use a different foreign key.

In this case, you'd have something like this:

class User
  has_many :relationships
  has_many :spouses, class_name: "Relationship", foreign_key: :spouse_id
end

User.first.spouses would then be a collection of all relationships where the user's id was present in the spouse_id field.