ruby on rails - Adding rows that are only associate with previous row -

i have table call municipalities , call forms. forms have 1 municipality, , stores variable called municipality_id.

when select state drop down menu, show municipalities state_id. @ point, want display forms associated municipality.

i'm having trouble getting municipality's forms show, , not of them.

here code far:

view:

 <div class="form-group">  <div> <% @municipalities.each |municipality| %>   <tr class="active">     <td><%= link_to municipality.name, municipality_path(municipality) %></td>     <td><%= municipality.state.state %></td>     <td><%= municipality.population %></td>     <% if user_signed_in? %>       <td><%= link_to 'show', municipality %></td>       <td><%= link_to 'edit', edit_municipality_path(municipality) %></td>       <td><%= link_to 'destroy', municipality, method: :delete, data: { confirm: 'are sure?' } %></td>     <% end %>       <% @forms.each |form| %>       <tr>         <%# if @forms.municipality_id == municipality %>           <% @forms.each |form| %>             <td><%= form.form_name %></td>           <% end %>           <%# end %>       <% end %>       <tr> <% end %> </div>        

controller:

  def index   @states = state.all    if params[:state_id].present?    @state = params[:state_id]    @municipalities = municipality.where(state_id: @state)    @forms = form.where(municipality_id: @municipalities)  else    @states = state.all    @municipalities = municipality.all  end 

end

schema:

 create_table "forms", force: :cascade |t| t.string   "form_name" t.string   "form_link" t.datetime "created_at",      null: false t.datetime "updated_at",      null: false t.integer  "municipality_id" t.integer  "department_id" end    add_index "forms", ["department_id"], name:    "index_forms_on_department_id"   add_index "forms", ["municipality_id"], name: "index_forms_on_municipality_id"  create_table "municipalities", force: :cascade |t|   t.string   "name"   t.integer  "form_id"   t.datetime "created_at", null: false   t.datetime "updated_at", null: false   t.integer  "population"   t.integer  "state_id" end 

any on how display forms associated municipality, after select state drop down. thanks!

fixed view, response below

 <%if @state != nil %>   <% @state.municipalities.each |municipality| %>    <tr class="active">     <td><%= link_to municipality.name, municipality_path(municipality) %></td>     <td><%= municipality.state.state %></td>     <td><%= municipality.population %></td>    </tr>     <% municipality.forms.each |form| %>    <tr>     <td><%= form.form_name %></td>    </tr>    <% end %>   <% end %>  <% end %> 

you want municipality have many forms, , form belong single municipality. therefore shouldn't define form_id in municipality table. there not one, multiple forms associated municipality.

in models define relations follows:

state.rb

has_many :municipalities 

municipality.rb

belongs_to :state has_many :forms 

form.rb

belongs_to :municipality 

then in controller load state @state = state.find(params[:state_id]. can iterate on municipalities in form @state.municipalities.each |municipality| , inside block municipality.forms.each |form|