"有個下拉式選單好方便"

來做好可以為 girb 編輯 level_cd 欄位的 view

app/views/girbs/edit.html.erb

<div class="container">
  <%= form_for @girb, :html => {:class => "form-horizontal center"} do |f| %>
  <div class="form-group">
    <%= f.label :name, "Name:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f.text_field :name, class: "form-control" %>
    </div>
  </div>
  <div class="form-group">
    <%= f.label :email, "Email:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f.text_field :email, class: "form-control" %>
    </div>
  </div>

  <div class="form-group">
    <%= f.label :level, "Level:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
    <%= f.collection_select :level_cd, Girb.all.select(:level_cd).distinct, :level_cd, :level, include_blank: true %>
    </div>
  </div>

  <div class="form-group">
    <%= f.label :like, "Like:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f.number_field :like, class: "form-control" %>
    </div>
  </div>
    <div class="form-group">
      <div class="col-md-3 control-label">
      </div>
      <div class="col-md-7">
          <%= f.submit "Submit", class: "btn btn-default btn-primary" %>
      </div>
  </div> 
  <% end %>
</div>





app/views/girbs/show.html.erb

<div class="container">
  <h2>Show Detail:</h2>
  <%= form_for @girb, :html => {:class => "form-horizontal center"} do |f| %>
  <div class="form-group">
    <%= f.label :name, "Name:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f.text_field :name, class: "form-control" %>
    </div>
  </div>
  <div class="form-group">
    <%= f.label :email, "Email:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
    <%= f.text_field :email, class: "form-control" %>
    </div>
  </div>


  <div class="form-group">
    <%= f.label :level_cd, "Level:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f.text_field :level, class: "form-control" %>
    </div>
  </div>

  <div class="form-group">
    <%= f.label :like, "Like:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f.text_field :like, class: "form-control" %>
    </div>
  </div>
  <% end %>
  <h2>Add a comment:</h2>
  <%= form_for([@girb, @girb.comments.build], :html => {:class => "form-horizontal center"} ) do |f2| %>
  <div class="form-group">
    <%= f2.label :commenter, "留言者:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f2.text_field :commenter, class: "form-control"  %>
    </div>
  </div>
  <div class="form-group">
    <%= f2.label :body, "內容:", class: "col-md-3 control-label" %>
    <div class="col-md-7">
      <%= f2.text_area :body, class: "form-control" %>
    </div>
  </div>
  <div class="form-group">
    <div class="col-md-3 control-label">
    </div>
    <div class="col-md-7">
      <%= f2.submit "留言", class: "btn btn-default btn-primary" %>
      <span class="pull-right">
      <%= link_to "back...", :back %></span>
    </div>
  </div>
  <% end %>

  <% if @girb.comments.all.count != 0 %>
  <h2>Comments:</h2>
  <% end %>
  <% @girb.comments.each do |comment| %>
  <% if comment.id != nil %>
  <div class="panel panel-default">
    留言者:<%= comment.commenter %><p>
    內容:<%= comment.body %>
  </div>
  <% end %>
  <% end %>

</div>





app/controllers/girbs_controller.rb

class GirbsController < ApplicationController

  def index
    @tab = params[:tab]
    if params[:search]
      @girbs = Girb.search(params[:search]).order("name DESC")
    else
      if @tab == "asc"
        @girbs = Girb.all.order("name ASC")
        @tab = "asc"
      elsif @tab == "desc"
        @girbs = Girb.all.order("name DESC")
      else
        @girbs = Girb.all
      end
    end
  end

    def label_fun_level
    "self.level"
  end

  def like_asc
    @at_like = false
    @girbs = Girb.all.order("like ASC")
    render :index
  end

  def like_desc
    @at_like = true
    @girbs = Girb.all.order("like DESC")
    render :index
  end

  def like
    @girb = Girb.find(params[:id])
    @girb.like += 1;
    @girb.save
    # redirect_to(girbs_path)
    redirect_to :back
  end

  def on_click_bang
    @girb = Girb.find(params[:id])
    @girb.bangs.create
    # redirect_to(girbs_path)
    redirect_to :back
  end

  def new
    @girb = Girb.new
  end

  def create
    @girb = Girb.new(girb_params)
    if @girb.save
      redirect_to(girbs_path)
    else
      render :new
    end
  end

  def show
    @girb = Girb.find(params[:id])
    # @comment = @girb.comments.build
  end

  def edit
    @girb = Girb.find(params[:id])
  end

  def update
    @girb = Girb.find(params[:id])
    if @girb.update(girb_params)
      redirect_to girbs_path
    else
      render :edit
    end
  end

  def destroy
    @girb = Girb.find(params[:id])
    @girb.destroy
    redirect_to girbs_path
  end

  private

  def girb_params
    params.require(:girb).permit(:name, :email, :like, :level_cd)
  end
end

OK 的話，現在應該可以成功的編輯 level_cd 這個欄位了
這邊注意一下，雖然編輯的是 level_cd
但呈現面是 level