Rails where with multiple conditions - ruby-on-rails

Question

In my application I have multiple user roles defined using an enum:
enum role: { staff: 0, clinician: 1, admin: 2 }
Staff users each belong to a university:
Staff Concern:
require 'active_support/concern'
module StaffUser
extend ActiveSupport::Concern
included do
belongs_to :university
has_many :patients
has_many :referral_requests
validates :university_id, presence: true, if: :staff?
end
University Model
class University < ApplicationRecord
has_many :staffs, -> { where role: :staff}, class_name: "User"
has_many :clinicians, through: :lists
has_many :whitelists
belongs_to :market
validates :market_id, presence: true
end
I have a dropdown select menu for Staff Doctor on a patients/new view where I want to display a list of staff users who belong to the same university as the current user, but I can't seem to get it to work. Currently, the dropdown only contains the prompt text. What am I doing wrong?
patients/new view:
<%= form_for(#patient) do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<div class="checkbox">
<h1>Tell us about your patient</h1>
<h2>Insurance</h2>
<% Insurance.all.each do |insurance| %>
<%= check_box_tag "patient[insurance_ids][]", insurance.id, #patient.insurance_ids.include?(insurance.id), id: dom_id(insurance) %>
<%= label_tag dom_id(insurance), insurance.name %><br>
<% end %>
<h2>Presenting Concerns</h2>
<% Concern.all.each do |concern| %>
<%= check_box_tag "patient[concern_ids][]", concern.id, #patient.concern_ids.include?(concern.id), id: dom_id(concern) %>
<%= label_tag dom_id(concern), concern.name %><br>
<% end %>
<h2>Staff Doctor</h2>
<%= select_tag "patient[staff_doctor_id]", options_from_collection_for_select(User.where("role = ? AND university_id = ?", "staff", #user.university_id), "id", "name"), prompt: "Select this patient's therapist" %>
</div>
<%= f.submit "Submit", class: "btn btn-primary" %>
<% end %
Patients Controller:
class PatientsController < ApplicationController
before_action :require_login
def new
#user = current_user
#patient = current_user.patients.build
end
def index
authorize Patient
#patients = policy_scope(Patient)
end
def show
#patient = Patient.find(params[:id])
end
def edit
#patient = Patient.find(params[:id])
end
def update
#patients = Patient.all
#patient = Patient.find(params[:id])
if #patient.update_attributes(patient_params)
flash[:success] = "Patient Updated!"
render 'patients/index'
else
render "edit"
end
end
def create
#patient = current_user.patients.build(patient_params)
if #patient.save
flash[:success] = "Patient Created!"
redirect_to new_referral_request_path(patient_id: #patient.id)
else
Rails.logger.info(#patient.errors.inspect)
render 'patients/new'
end
end
private
def patient_params
params.require(:patient).permit(:age, :staff_doctor_id, :user_id, insurance_ids: [], gender_ids: [], concern_ids: [], race_ids: [])
end
end

Answer 1

Scopes in ActiveRecord are chainable:
User.staff.where(university: #user.university)
Chaining .where or scopes creates AND clauses. So all the conditions must apply.
Using ActiveRecord::Enum creates scopes for each of the enum states. So this is equivilent to:
User.where(role: :staff, university: #user.university)
When using an ActiveRecord::Enum you need to remember that the database stores integers - not strings:
User.where('role = 0') # staff
User.where('role = ?', User.statuses[:staff])
But there is no need to use a SQL string for this query.
A much better way to create selects and checkboxes is by using the rails collection helpers:
<%= form_for(#patient) do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<div class="checkbox">
<h1>Tell us about your patient</h1>
<h2>Insurance</h2>
<%= f.collection_check_boxes(:insurance_ids, Insurance.all, :id, :name) %>
<h2>Presenting Concerns</h2>
<%= f.collection_check_boxes(:concern_ids, Concern.all, :id, :name) %>
<h2>Staff Doctor</h2>
<%= f.collection_select(:staff_doctor_id, User.staff.where(university: #user.university), :id, :name, prompt: "Select this patient's therapist") %>
</div>
<%= f.submit "Submit", class: "btn btn-primary" %>
<% end %>
Not only is this a lot less code, but binding the inputs to the form builder ensures that they "hold the value" when validations fail.