Updating 2 tables with one form Ruby on rails and MySQL database.

Let's create 2 models that are related to each other...

parent model : Product with name attribute.

child model: Imaged with URL attribute.

rails g model Image url:string

rails g scaffold Product name:string references Image

Next set-up MySQL database from this link:

https://www.ionos.com/digitalguide/server/know-how/use-mysql-with-ruby-on-rails/

after setting up the db...

user the product controller to update both the 2 models.

like this in product controller:

class ProductsController < ApplicationController
before_action :set_product, only: %i[ show edit update destroy ]

# GET /products or /products.json
def index
@products = Product.all

end

# GET /products/1 or /products/1.json
def show
end

# GET /products/new
def new
@product = Product.new
@image=@product.build_image
end

# GET /products/1/edit
def edit
end

# POST /products or /products.json
def create
@product = Product.new(product_params)
respond_to do |format|
if @product.save
format.html { redirect_to @product, notice: "Product was successfully created." }
format.json { render :show, status: :created, location: @product }
else
format.html { render :new, status: :unprocessable_entity }
format.json { render json: @product.errors, status: :unprocessable_entity }
end
end
end

# PATCH/PUT /products/1 or /products/1.json
def update
respond_to do |format|
if @product.update(product_params)
format.html { redirect_to @product, notice: "Product was successfully updated." }
format.json { render :show, status: :ok, location: @product }
else
format.html { render :edit, status: :unprocessable_entity }
format.json { render json: @product.errors, status: :unprocessable_entity }
end
end
end

# DELETE /products/1 or /products/1.json
def destroy
@product.destroy
respond_to do |format|
format.html { redirect_to products_url, notice: "Product was successfully destroyed." }
format.json { head :no_content }
end
end

private
# Use callbacks to share common setup or constraints between actions.
def set_product
@product = Product.find(params[:id])
end

# Only allow a list of trusted parameters through.
def product_params
  params.require(:product).permit(:name,
  image_attributes:[:url]
  )
end

end

Next.....

update the _form.html.erb on product views:

we want to give to combine both the models with one form:

<%= form_with(model: product) do |form| %>
<% if product.errors.any? %>

<%= pluralize(product.errors.count, "error") %> prohibited this product from being saved:

  <ul>
    <% product.errors.each do |error| %>
      <li><%= error.full_message %></li>
    <% end %>
  </ul>
</div>

<% end %>

<% 3.times do %>

<%= form.label :name %>
<%= form.text_field :name %>

<%= form.fields_for :image do |form| %>

<%= form.label :url %>
<%= form.text_field :url %>
<%= form.label :alt %>
<%= form.text_field :alt %>
<% end %>
<% end %>
<%= form.label :name %>
<%= form.text_field :name %>

<%= form.fields_for :image do |form| %>

<%= form.label :url %>
<%= form.text_field :url %>
<%= form.label :alt %>
<%= form.text_field :alt %>
<% end %>
<%= form.submit %>

<% end %>

lastly: update the the 2 models:

product.rb

class Product < ApplicationRecord
has_one :image,dependent: :destroy
accepts_nested_attributes_for :image
end

image.rb

class Image < ApplicationRecord
belongs_to :product
end

if you guys have question about that.. you can ask me. Goodluck.