Rails has_one Association (user,company) - ruby-on-rails

Question

class User < ActiveRecord::Base
has_one :comapny
end
class Comapny < ApplicationRecord
belongs_to :user
end
Hi! i created rails association mentioned above. I want user to create only one company (for example: User with id(1) should only make 1 company only).
But even with has_one i am able to make more then 1 company for user1.
can anyone help?
user_controller.rb
class UsersController < ApplicationController
before_action :set_user, only: [:edit, :update, :show]
before_action :require_user, only: [:index, :show, :update ]
before_action :require_same_user, only: [:edit, :destroy, :update]
before_action :require_admin, only: [:destroy]
def index
#user = User.all
end
def new
#user = User.new
end
def create
#user = User.new(user_params)
if #user.save
session[:user_id] = #user.id
flash[:success] = "Welcome #{#user.username}"
redirect_to user_path(#user)
else
render 'new'
end
end
def edit
#user = User.find(params[:id])
end
def update
#user = User.find(params[:id])
if #user.update(user_params)
flash[:success] = "Account was updated"
else
render 'new'
end
end
def show
end
def destroy
#user = User.find(params[:id])
#user.destroy
flash[:danger] = "User is destroyed"
redirect_to root_path
end
private
def user_params
params.require(:user).permit(:username, :email, :password, :role, :first_name, :last_name)
end
def set_user
#user = User.find(params[:id])
end
def require_same_user
if current_user != #user and !current_user.admin?
flash[:danger] = "Not authorized"
redirect_to user_path
end
end
def require_admin
if logged_in? and !current_user.admin?
flash[:danger] = "Not authorized"
redirect_to user_path
end
end
end
**comapny_controller.rb**
class ComapniesController < ApplicationController
before_action :set_comapny, only: %i[ show edit update destroy ]
before_action :require_user, only: [:create]
# GET /comapnies or /comapnies.json
def index
#comapnies = Comapny.all
end
# GET /comapnies/1 or /comapnies/1.json
def show
end
# GET /comapnies/new
def new
#comapny = Comapny.new
end
# GET /comapnies/1/edit
def edit
end
# POST /comapnies or /comapnies.json
def create
#comapny = Comapny.new(comapny_params)
respond_to do |format|
if #comapny.save
format.html { redirect_to comapny_url(#comapny), notice: "Comapny was successfully created." }
format.json { render :show, status: :created, location: #comapny }
else
format.html { render :new, status: :unprocessable_entity }
format.json { render json: #comapny.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /comapnies/1 or /comapnies/1.json
def update
respond_to do |format|
if #comapny.update(comapny_params)
format.html { redirect_to comapny_url(#comapny), notice: "Comapny was successfully updated." }
format.json { render :show, status: :ok, location: #comapny }
else
format.html { render :edit, status: :unprocessable_entity }
format.json { render json: #comapny.errors, status: :unprocessable_entity }
end
end
end
# DELETE /comapnies/1 or /comapnies/1.json
def destroy
#comapny.destroy
respond_to do |format|
format.html { redirect_to comapnies_url, notice: "Comapny was successfully destroyed." }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_comapny
#comapny = Comapny.find(params[:id])
end
# Only allow a list of trusted parameters through.
def comapny_params
params.require(:comapny).permit(:name, :year_founded, :user_id)
end
end
**Coampny_form.html.erb**
<%= form_with(model: comapny, local: true) do |form| %>
<% if comapny.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(comapny.errors.count, "error") %> prohibited this comapny from being saved:</h2>
<ul>
<% comapny.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= form.label :name %>
<%= form.text_field :name, id: :comapny_name %>
</div>
<div class="field">
<%= form.label :year_founded %>
<%= form.date_select :year_founded, id: :comapny_year_founded %>
</div>
<div class="field">
<%= form.label :user_id %>
<%= form.text_field :user_id, id: :comapny_user_id, value: current_user.id %>
</div>
<div class="actions">
<%= form.submit %>
</div>
<% end %>
I made a typo while generating scaffold of coapmny instead of company. ignore that

Answer 1

Add a uniqueness constraint to the db table and a uniqueness validation to the company model:
class Comapny < ApplicationRecord
belongs_to :user
validates :user_id, uniqueness: true
end