如何在嵌套模型rails 6中从子模型中获取父对象

class Child < ApplicationRecord
  belongs_to :parent
end

class ChildrenController < ApplicationController
  def create
    @parent = Parent.find(params[:parent_id])
    @child = @parent.children.build(child_params)

    if @child.save
      # 保存成功的逻辑
    else
      # 保存失败的逻辑
    end
  end

  private

  def child_params
    params.require(:child).permit(:name)
  end
end

<%= form_with(model: [@parent, @child]) do |form| %>
  <%= form.hidden_field :parent_id %>

  <!-- 其他表单字段 -->

  <%= form.submit %>
<% end %>