user controller and model

app/controllers/users_controller.rb

@@ -0,0 +1,56 @@
+class UsersController < ApplicationController
+  def index
+    matching_users = User.all
+
+    @list_of_users = matching_users.order({ :created_at => :desc })
+
+    render({ :template => "users/index" })
+  end
+
+  def show
+    the_id = params.fetch("path_id")
+
+    matching_users = User.where({ :id => the_id })
+
+    @the_user = matching_users.at(0)
+
+    render({ :template => "users/show" })
+  end
+
+  def create
+    the_user = User.new
+    the_user.email = params.fetch("query_email")
+    the_user.password = params.fetch("query_password")
+
+    if the_user.valid?
+      the_user.save
+      redirect_to("/users", { :notice => "User created successfully." })
+    else
+      redirect_to("/users", { :alert => the_user.errors.full_messages.to_sentence })
+    end
+  end
+
+  def update
+    the_id = params.fetch("path_id")
+    the_user = User.where({ :id => the_id }).at(0)
+
+    the_user.email = params.fetch("query_email")
+    the_user.password = params.fetch("query_password")
+
+    if the_user.valid?
+      the_user.save
+      redirect_to("/users/#{the_user.id}", { :notice => "User updated successfully."} )
+    else
+      redirect_to("/users/#{the_user.id}", { :alert => the_user.errors.full_messages.to_sentence })
+    end
+  end
+
+  def destroy
+    the_id = params.fetch("path_id")
+    the_user = User.where({ :id => the_id }).at(0)
+
+    the_user.destroy
+
+    redirect_to("/users", { :notice => "User deleted successfully."} )
+  end
+end

app/models/user.rb

@@ -0,0 +1,24 @@
+# == Schema Information
+#
+# Table name: users
+#
+#  id                     :bigint           not null, primary key
+#  email                  :string           default(""), not null
+#  encrypted_password     :string           default(""), not null
+#  remember_created_at    :datetime
+#  reset_password_sent_at :datetime
+#  reset_password_token   :string
+#  created_at             :datetime         not null
+#  updated_at             :datetime         not null
+#
+# Indexes
+#
+#  index_users_on_email                 (email) UNIQUE
+#  index_users_on_reset_password_token  (reset_password_token) UNIQUE
+#
+class User < ApplicationRecord
+  # Include default devise modules. Others available are:
+  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
+  devise :database_authenticatable, :registerable,
+         :recoverable, :rememberable, :validatable
+end

config/routes.rb

@@ -1,4 +1,5 @@
 Rails.application.routes.draw do
+  devise_for :users
   # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
 
   # Defines the root path route ("/")

db/migrate/20241023035916_devise_create_users.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+class DeviseCreateUsers < ActiveRecord::Migration[7.1]
+  def change
+    create_table :users do |t|
+      ## Database authenticatable
+      t.string :email,              null: false, default: ""
+      t.string :encrypted_password, null: false, default: ""
+
+      ## Recoverable
+      t.string   :reset_password_token
+      t.datetime :reset_password_sent_at
+
+      ## Rememberable
+      t.datetime :remember_created_at
+
+      ## Trackable
+      # t.integer  :sign_in_count, default: 0, null: false
+      # t.datetime :current_sign_in_at
+      # t.datetime :last_sign_in_at
+      # t.string   :current_sign_in_ip
+      # t.string   :last_sign_in_ip
+
+      ## Confirmable
+      # t.string   :confirmation_token
+      # t.datetime :confirmed_at
+      # t.datetime :confirmation_sent_at
+      # t.string   :unconfirmed_email # Only if using reconfirmable
+
+      ## Lockable
+      # t.integer  :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
+      # t.string   :unlock_token # Only if unlock strategy is :email or :both
+      # t.datetime :locked_at
+
+
+      t.timestamps null: false
+    end
+
+    add_index :users, :email,                unique: true
+    add_index :users, :reset_password_token, unique: true
+    # add_index :users, :confirmation_token,   unique: true
+    # add_index :users, :unlock_token,         unique: true
+  end
+end