TOPIC:

$this->execPieceByName('ff_InitLib');

if ( ( $recId = JRequest::getVar('record_id') ) != '' ) {
  ff_updateCustom($this->submitdata, 'Your_Select_List_Element_Name', $recId);
}
// This function will take care of updating the #__facileforms_subrecords table with the proper values
// - for $submits  passing $this->submitdata
// - for $elementName  pass in the name of the element whose value you wish to update
// - $recId takes the record id of the element beign edited. If it is not set, it a new record and there is nothing update in the table
function ff_updateCustom($submits, $elementName, $recId) {
  foreach ($submits as $sub) {
    if ($sub[1] == $elementName) {

      $inputName = $sub[1];
      $inputValue = $sub[4];

      $db = JFactory::getDBO();
      $db->setQuery("Select id from #__facileforms_subrecords Where name = '$inputName' And record = $recId ");
      if ($db->loadResult()) {
        $db->setQuery("Update #__facileforms_subrecords Set value = '$inputValue' Where name = '$inputName' And record = $recId ");
      } else {
        $inputElement = $sub[0];
        $inputTitle = $sub[2];
        $inputType = $sub[3];

        $db->setQuery("Insert into #__facileforms_subrecords ( record, element, title, name, type, value ) values ( $recId, $inputElement, '$inputTitle', '$inputName', '$inputType', '$inputValue' ) ");
      }
      $db->query();
    }
  }
}