ERROR: relation "product_categories_products" does not exist LINE 1: DELETE FROM "product_categories_products" WHERE "product_cat...

index.html.erb

<h3>Product Categories</h3>

<div class="large-4 columns">
  <%= render 'form' %>
</div>
<div class="large-8 columns">
<table>
  <thead>
    <tr>
      <th width="300">Name</th>
      <th></th>
      <th></th>
    </tr>
  </thead>

  <tbody>
    <% @product_categories.each do |product_category| %>
      <tr>
        <td><%= product_category.name %></td>
        <td><%= link_to 'Edit', edit_admin_product_category_path(@product_categories) %></td>
        <td><%= link_to 'Destroy', admin_product_category_path(product_category), method: :delete, data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>
</div>
<br>

product_categories_controller.rb

  def destroy
    @product_category.destroy
    respond_to do |format|
      format.html { redirect_to [:admin_product_categories, @product_categories] }
      format.json { head :no_content }
    end
  end

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