Model has 2 foreign keys. Cant insert foreign key into the table of an other table. mysql database. ruby on rails app -

i having problems rails application. have 3 tables( skill, version, , skillversion). skillversion has 2 foreign key columns skill , version) have form skillversion , every time add skill associated version, should add skill , use version drop down list(gets list version table).

issue: when submit form. adding new version row in version table different id. dont want add different row if similar version exists. after submitting skillversion table, should id of existing version , add version_id column in skillversion. please , let me know if need more information. attaching relevant code project.

right now: doesnt add value skillversion table

model/skill.rb

class skill < activerecord::base     has_many :skillversions end 

model/skilversion.rb

class skillversion < activerecord::base belongs_to :skill belongs_to :version end 

model/version.rb

class version < activerecord::base     has_many :skillversions end 

controllers/skillversions_controller.rb

    def create     @version = version.find(:number)     @skill = skill.new(params[:skill].permit(:name))      if @skill.save         @skillversion = skillversion.new(params[:skillversion].permit(:version_id, :isactive))         @skillversion.skill = @skill         @skillversion.version = @version         if @skillversion.save             redirect_to skillversions_index_path         else             render json: @skillversion.errors, status: :internal_server_error         end      end         render json: @skill.errors, status: :internal_server_error end 

views/skillversions/_form.html.erb

<%= fields_for :skill |s| %> <%= fields_for :version |v| %> <form class="form-horizontal" id="dform">   <div class="control-group">     <%= s.label :name, 'skill name', :class => "control-label" %>     <div class="controls">       <%= s.text_field :name, :class => "controls" %>     </div>   </div>   <div class="control-group">     <%= v.label :number, 'version', :class => "control-label" %>     <div class="controls" >       <%= v.collection_select :number, version.find(:all), :id, :number,  :class => "dropdownwidth" %>     </div>   </div>   <div class="control-group">     <div class="controls">       <label class="checkbox" >         <%= sv.check_box :isactive, :class => "controls " %>         <%= sv.label :isactive, 'active?', :class => "checkbox" %>       </label>       <%= sv.submit 'create it!', :class => "metro" %>     </div>   </div> </form> <% end %> <% end %> 

thank in advance!