向数据库中的两个表提交一份表单- rails

Question

我有两个表，landslides和sources (可能没有关联)。我想要一个表格，让用户填写信息，然后提交给两个表格。下面是没有sources字段的当前表单：

 = form_for :landslide, :url => {:controller => 'landslides', :action => 'create'} do |f|

      .form-inputs
        %form#landslideForm
          .form-group.row
            %label.col-sm-2.col-form-label{for: "textinput"}Date
            .col-sm-10
              = f.date_select :start_date, :class => "form-control"
          #Some fields
     .form-actions
        = f.button :submit, class: "btn btn-lg btn-primary col-sm-offset-5", id: "submitButton"

和参数：

    def landslide_params
          params.require(:landslide).permit(:start_date, :continent, :country, :location, :landslide_type, :lat, :lng, :mapped, :trigger, :spatial_area, :fatalities, :injuries, :notes)
    end

    def source_params
      params.require(:source).permit(:url, :text, :landslide_id)
    end

此外，sources中还有一个列调用landslide_id，它从表landslides中获取滑坡ID。因此，当用户提交新的滑坡时，我如何获得即将到来的滑坡ID (这是自动增量，用户不需要填写)？

谢谢!

Answer 1

HTML不允许嵌套的<form>元素，并且不能传递尚未通过表单持久化的记录id (因为它没有id)。

若要在同一个请求中创建嵌套资源，请使用accepts_nested_attributes_for

class Landslide
  # or has_many
  has_one :source
  accepts_nested_attributes_for :source    
end

class Source
  belongs_to :landslide
end

这意味着您可以执行Landslide.create(source_attributes: { foo: 'bar' })，它将同时创建Landslide和Source记录，并将通过sources.landslide_id自动链接它们。

要创建表单输入，请使用fields_for

# use convention over configuration
= form_for @landslide do |f|
  .form-inputs
    .form-group.row
      # use the form builder to create labels instead
      = f.label :start_date, class: 'col-sm-2 col-form-label'
      .col-sm-10
        = f.date_select :start_date, class: "form-control"
   %fieldset
      %legend Source
      = f.fields_for :sources do |s|
        .form-group.row
          = s.label :url, class: 'col-sm-2 col-form-label'
          .col-sm-10
            = s.text_field :url, class: "form-control"
        # ...

class LandslidesController

  # ...

  def new
    @landslide = Landslide.new
    # this is needed to seed the form with inputs for source
    @landslide.source.new 
  end

  def create
    @landslide = Landslide.new(landslide_params)
    if @landslide.save
      redirect_to @landslide
    else
      @landslide.source.new unless @landslide.source.any?
      render :new
    end
  end

  private
  def landslide_params
    params.require(:landslide).permit(
      :start_date, :continent, :country, 
      :location, :landslide_type, 
      :lat, :lng, :mapped, :trigger, :spatial_area, 
      :fatalities, :injuries, :notes,
      source_attributes: [ :url, :text ]
    )
  end
end

Answer 2

您需要使用accept_nested_attributes_for并相应地嵌套表单：

(对于应该嵌套哪种形式，我有保留，我以通过滑坡形式提交的源为例。)

在landslide.rb中

accept_nested_attributes_for :sources

在你看来(我不认识哈梅尔，但无论如何)

<%= form_for :landslide do |f|%>
  <%= f.select :start_date %>

    <%= fields_for :sources do |s| %>
      <%= s.input :your_column %>
    <% end %>

   <%= f.button :submit %>
<% end %>

顺便说一下，已经有很多问题了，这就是所谓的“嵌套表单”

many relation

for not working?

for in rails view