Rails has_many :through with different column name in association table

ruby-on-rails, ruby-on-rails-3

Solution

You should use the `:foreign_key` option in `Assignment`, e.g.:

class Assignment
  belongs_to :user, :foreign_key => :contractor_id
  belongs_to :project

Problem

I currently have two different models: `User` and `Project`. The `User` model has three types of users - owners, contractors and clients. I want to assign multiple contractors to one project. I am trying this with a `has_many :through` association, like so: ``` Class User has_many :assignments has_many :projects, :through => :assignments Class Project has_many :assignments has_many :contractors, :through => :assignments Class Assignment belongs_to :user belongs_to :project ``` My issue is in using `contractor_id` in the `assignments` table instead of `user_id`. In my `assignments` table I currently have columns `contractor_id` and `project_id`. Everything seems to work if I use `user_id` instead, but that will cause things to be pretty messy later on in my views. How would I accomplish this?

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