CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-4has-many-through
csi
csi

Reputation: 9328

Concatenate columns in rails has_many through relationship

Physician has_many Patients through Appointments
Patient has_many Physicians through Appointments

How can I make the Appointment name a concatenation of Physician name and Patient name automatically in the Appointment model? 

Physician.name = 'Joe Doctor'  
Patient.name = ' Sally Smith'  
Appointment.name = "#{Patient.name} with #{Physician.name}"

This is not our real world use but a simplified example. Thanks.

Upvotes: 0

Views: 135

Answers (2)

charlysisto
charlysisto

Reputation: 3700

One way of doing it would be :

class Appointment
  belongs_to :doctor
  belongs_to :patient

  before_create :set_default_name #optional it can be called imperatively

  def set_default_name
    if patient && doctor
      self.name= "#{patient.name} with #{doctor.name}"
    end
  end
end

That way whenever you add a patient to a doctor.patients it should set the appointment's name automatically:

@doctor.patients << @patient
@doctor.appointments.last.name # => "Dr Who with Mr Spock"

Upvotes: 2

Yang
Yang

Reputation: 1923

Assume you have one patient and one physician in each appointment, you can define a method in your Appointment model like:

def name
  self.patient.name + ' with ' + self.physician.name
end

Upvotes: 1

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