Adding Dummy Column in Kohana ORM

问题

I want to add dummy column in kohana ORM . I have a field of type longtext . I want to have a new field which contains it's strlen.

回答1:

Use $_ignored_columns property:

protected $_ignored_columns = array('text_length');

public function __get($column)
{
   if ($column == 'text_length' && (! isset($this->_object['text_length']) || isset($this->_changed['text'])))
   {
      // recalc dummy field if not set, or on long text value changing
      return $this->_object['text_length'] = strlen($this->_object['text']);
   }

   return parent::__get($column);
}

来源：https://stackoverflow.com/questions/5659291/adding-dummy-column-in-kohana-orm