Rails 4 nested attributes multiple records insert instead updating

I'm stuck and i don't know why it is not working right. I have a model
lesson wich has many sublessons. When i update the lesson rails update
properly the lesson attributes but is creating another sublessons
records instead of just updating it.
Here is my code
View Form:
<div style="padding:13px">
<%= form_for @lesson do |f| %>
<%= f.label :lesson_name, "Lesson title" %></br>
<%= f.text_field :lesson_name, class: "form-control" %></br>
<%= f.label :lesson_icon, "Choise icon" %>
<%= f.select "lesson_icon", options_for_select([ "ico03",
"ico04","ico05","ico06" ])%></br></br>
<%= f.fields_for :sublessons do |sublesson_a| %>
<%= sublesson_a.label :sublesson_name, "Subtitle 1" %></br>
<%= sublesson_a.text_field :sublesson_name, class:
"form-control" %></br>
<%= sublesson_a.label :sublesson_content, "Content" %></br>
<%=sublesson_a.text_area 'sublesson_content', rows: 3, class:
<%= sublesson_a.label :sublesson_video_link, "Video link"
<%= sublesson_a.text_field :sublesson_video_link, class:
"form-control" %></br>
<%= f.submit "Submit", class: "btn btn-primary" %>
<% end %>
lesson model
class Lesson < ActiveRecord::Base
has_many :sublessons, :dependent => :destroy
accepts_nested_attributes_for :sublessons, :reject_if => :all_blank
sublesson model
class Sublesson < ActiveRecord::Base
belongs_to :lesson, :foreign_key => "lesson_id"
validates :sublesson_name, presence: true
validates :sublesson_content ,presence: true
lesson controller
def update
@lesson = Lesson.find(params[:id])
if @lesson.update(lesson_params)
flash[:notice] = "Lesson updated"
redirect_to lessons_show_url
flash[:notice] = "Error"
redirect_to lessons_show_url
def edit
@lesson = Lesson.find(params[:id])
def lesson_params
params.require(:lesson).permit(:lesson_name, :lesson_icon,
sublessons_attributes:[:sublesson_id, :sublesson_name,
:sublesson_content, :sublesson_video_link])

Hi Marius,

Can you try adding the :id attribute to the :sublessons_attributes array in lesson_params? You need to permit the id attribute.


Thanks Steve, but now is give me error message...i write :id instead of
sublesson_id ...This :id where do he come from from?


Marius… not instead of :sublesson_id. You need to add the :id attribute in addition to the other nested attributes.

Btw, :id is generated as a hidden field by fields_for. Check here: http://apidock.com/rails/ActionView/Helpers/FormHelper/fields_for


Thanks Steve it's working... i have this hidden fields for adding
anothers sublessons and it's seems like it's generating some nasty
ids...if i want to create and update same time i have to make another
method i think....i 'm new to this business i'm struggle to learn the
conceps...i came from php wordpress and there are diferent stuff
<%= f.fields_for :sublessons do |sublesson_aa| %>
           <div class="add_new_subtitle delete-subtitle-<%=hh%>"
style="padding-bottom: 25px;">
            <%= sublesson_aa.label :sublesson_name, "Subtitle 1"
            <%= sublesson_aa.text_field :sublesson_name, class:
"form-control delete-sublesson-field-#{hh}", :value => ""%></br>
            <%= sublesson_aa.label :sublesson_content, "Content" %></br>
            <%=sublesson_aa.text_area 'sublesson_content', rows: 3,
class: "form-control delete-sublesson-content-#{hh}", :value =>
            <%= sublesson_aa.label :sublesson_video_link, "Video link"
            <%= sublesson_aa.text_field :sublesson_video_link, class:
"form-control delete-sublesson-video-#{hh}", :value => "" %></br>
            <a style="float:right" class="btn btn-primary"
id="remove_sublesson" onclick="remove_sublesson(<%=hh%>)">Delete
            <p style="display:none"><%= hh=hh+1%></p>


Maurius. I am not able to understand your second question :slight_smile: Would be nice if you started a new thread with detailed explanation. Btw, there are a lot of resources already that show how to do this sorta stuff. Just do some searching. If you dont find luck then I suggest start a new one :slight_smile:

Thanks man,

I am working on Address book and i face problem regarding how to added
dynamic column by each user. one things is each user display its own
column after add column how to submit all values inside one form.

view (e.g consider mike is user and its create name,city and address
dynamic column how three row inserted into database. )

<h1>Add Field values</h1>

<%= form_for(:detail, :url => {:controller => 'details', :action =>
'create'}) do |f| %>

  <% @info.each do |a| %>
    <%= f.hidden_field :columns_id, :value =>a.id %>
      <td><%= a.value %></td>
      <td><%= f.text_field :column_value %></td>
  <% end %>

  <%= f.hidden_field :users_id, :value => current_user.id %>
  <p class="button"><%= f.submit %></p>

<% end %>


class DetailsController < ApplicationController
  def new
      @detail = Detail.new
       @info = Column.where(:users_id => current_user.id).all

  def create
    @detail = Detail.new(user_params)
    if @detail.save
      redirect_to new_detail_path, :notice => "Added Sucessfully!"
      render "new"


  def user_params