Best way to update Has_many Joined Table

Question

right now I have a jobs table with

  has_many :applicants
  has_many:users, through: :applicants

and a applicant table with

belongs_to :job
belongs_to :user

and a user table with

has_many :applicants
has_many:jobs, through: :applicants

So Users are connected through applicant table to Jobs table and vise versa.

I'm not sure I'm updating the model correctly. Right now it looks like this:

def addapply
    @job = Job.find(params[:id])
    applicant = Applicant.find_or_initialize_by(job_id: @job.id)
    applicant.update(user_id: current_user.id)
    redirect_to @job
end

But I got to thinking - would not this replace whatever association was there before?

I started looking around and found this in someone else's code:

def update

  unless params[:user_relationships][:user_category_ids]
    # Set default user category if not selected.
    @user.user_category_relationships.build(
      :category_id        => '1',
      :created_by_user_id => @current_user.id,
      :name_id            => @name.id
    )
  else
    params[:user_relationships][:user_category_ids].each { |user_category_id|
      @user.user_category_relationships.build(
        :category_id        => user_category_id,
        :created_by_user_id => @current_user.id,
        :name_id            => @name.id
      )
    }
  end
end

I'm not sure how that all works but perhaps I do need to iterate through them with a .each before I update.

I don't want to replace what is already there, I just want to add to it.

In Short what is the best way to update (or rather add to) a has_many :through joined table association?

Answer 1

Why not?

def addapply
  @job = Job.find(params[:id])
  applicant = Applicant.where(job_id: @job.id, user_id: current_user.id).first_or_create
  redirect_to @job
end