#1.1 create patient model

app/models/doctor.rb

@@ -0,0 +1,12 @@
+class Doctor < ApplicationRecord
+
+  validates :first_name, :last_name, :practicing_from, :qualification_number, :employment, presence: true
+  validates_uniqueness_of :qualification_number
+
+  enum employment: {
+    full_time: 0,
+    part_time: 1,
+    intern: 2,
+    contract: 3
+  }
+end

app/models/patient.rb

@@ -0,0 +1,10 @@
+class Patient < ApplicationRecord
+
+  validates :first_name, :last_name, :age, presence: true
+
+  enum gender: {
+    male: 0,
+    female: 1,
+    other: 2
+  }
+end

db/migrate/20191120224317_create_patients.rb

@@ -0,0 +1,11 @@
+class CreatePatients < ActiveRecord::Migration[5.2]
+  def change
+    create_table :patients do |t|
+      t.string :first_name, null: false
+      t.string :last_name, null: false
+      t.integer :age, null: false
+      t.integer :gender, null: false
+      t.timestamps
+    end
+  end
+end

db/migrate/20191120225245_create_doctors.rb

@@ -0,0 +1,14 @@
+class CreateDoctors < ActiveRecord::Migration[5.2]
+  def change
+    create_table :doctors do |t|
+      t.string :first_name, null: false
+      t.string :last_name, null: false
+      t.timestamp :practicing_from, null: false
+      t.integer :qualification_number, null: false
+      t.integer :employment, null: false, default: 0
+      t.timestamps
+    end
+
+    add_index :doctors, :qualification_number, unique: true
+  end
+end

db/schema.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 # This file is auto-generated from the current state of the database. Instead
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
@@ -12,7 +10,29 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 0) do
+ActiveRecord::Schema.define(version: 2019_11_20_225245) do
+
   # These are extensions that must be enabled in order to support this database
-  enable_extension 'plpgsql'
+  enable_extension "plpgsql"
+
+  create_table "doctors", force: :cascade do |t|
+    t.string "first_name", null: false
+    t.string "last_name", null: false
+    t.datetime "practicing_from", null: false
+    t.integer "qualification_number", null: false
+    t.integer "employment", default: 0, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["qualification_number"], name: "index_doctors_on_qualification_number", unique: true
+  end
+
+  create_table "patients", force: :cascade do |t|
+    t.string "first_name", null: false
+    t.string "last_name", null: false
+    t.integer "age", null: false
+    t.integer "gender", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
 end

spec/factories/doctors.rb

@@ -0,0 +1,9 @@
+FactoryBot.define do
+  factory :doctor do
+    first_name { Faker::Name.first_name }
+    last_name { Faker::Name.last_name }
+    practicing_from { Time.current - rand(20).years }
+    sequence(:qualification_number) { |n| n }
+    employment { 0 }
+  end
+end

spec/factories/patients.rb

@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :patient do
+    first_name { Faker::Name.first_name }
+    last_name { Faker::Name.last_name }
+    age { rand(100) }
+    gender { 1 }
+  end
+end

spec/models/doctor_spec.rb

@@ -0,0 +1,21 @@
+require 'rails_helper'
+
+describe Doctor do
+  context 'validations' do
+    it { should validate_presence_of :first_name }
+    it { should validate_presence_of :last_name }
+    it { should validate_presence_of :practicing_from }
+    it { should validate_presence_of :qualification_number }
+    it { should validate_presence_of :employment }
+
+    context 'uniqueness' do
+      let!(:doctor) { create(:doctor) }
+
+      it { should validate_uniqueness_of(:qualification_number) }
+    end
+  end
+
+  context 'enumerators' do
+    it { should define_enum_for(:employment).with_values(%w(full_time part_time intern contract)) }
+  end
+end

spec/models/patient_spec.rb

@@ -0,0 +1,13 @@
+require 'rails_helper'
+
+describe Patient do
+  context 'validations' do
+    it { should validate_presence_of :first_name }
+    it { should validate_presence_of :last_name }
+    it { should validate_presence_of :age }
+  end
+
+  context 'enumerators' do
+    it { should define_enum_for(:gender).with_values(%w(male female other)) }
+  end
+end