使用belongs_to关联将隐藏字段放入资源的表单中的任何方式

<%= form_with(model: resource) do |form| %>
  <%= form.hidden_field :association_id, value: @association.id %>
  ...
<% end %>

<%= form_with(model: resource) do |form| %>
  <%= hidden_field_tag "resource[association_id]", @association.id %>
  ...
<% end %>

<%= form_with(model: resource) do |form| %>
  <%= form.fields_for :association, @association do |association_form| %>
    <%= association_form.hidden_field :id %>
  <% end %>
  ...
<% end %>