doctor.rb

# Before using, download the database [from the lecture](http://karr.lewagon.org/assets/02_sql_crud_doctors-cf43cfaf07025130e638de583d55e0ec.db) 
# and save it as "doctors.db" in the same folder as this file

require 'sqlite3'
DB = SQLite3::Database.new("doctors.db")

class Doctor
  attr_reader :id
  attr_accessor :name, :age, :specialty

  def initialize(attributes)
    @id = attributes[:id]
    @name = attributes[:name]
    @age = attributes[:age]
    @speciality = attributes[:specialty]
  end

  # Get all Doctors (class method as don't need an object to call it)
  def self.all
    DB.execute("SELECT * FROM doctors;").map do |row|
      Doctor.new(id: row[0], name: row[1], age: row[2], specialty: row[3])
    end
  end

  # Get a single Doctor from its id (class method as don't need an object to call it)
  def self.find(id)
    # Retrieve record from db
    row = DB.execute("SELECT * FROM doctors WHERE id = ?;", id).first 
  
    # Create a new Doctor object
    Doctor.new(id: row[0], name: row[1], age: row[2], specialty: row[3])
  end

  # Destroy the current doctor (instance method)
  def destroy
    DB.execute("DELETE FROM doctors WHERE id = ?;", @id) 
  end

  # Save the current doctor (instance method)
  def save
    if(@id)
      DB.execute("UPDATE doctors set name = ?, age = ?, specialty = ? WHERE id = ?;", 
        @name, 
        @age, 
        @specialty,
        @id
      )
    else
      DB.execute("INSERT INTO doctors (name, age, specialty) VALUES (?, ?, ?);", 
        @name, 
        @age, 
        @specialty
      )
      @id = DB.last_insert_row_id
    end
  end
end

# Create a new Doctor:

# green = Doctor.new(name: "Green", age: 25, specialty: "Oncologist")
# green.save

# Find all doctors:

# doctors = Doctor.all

# Find a single Doctor

# john = Doctor.find(1)

# Destroy a Doctor

# john.destroy