Kohana 3.1 ORM：将空模型属性值保存为0（零）而不是NULL

Question

I have two models, Product and Product_Methodology. In my product edit view I have a select form field to select one of many methodologies or none (empty first option). In my products table I have a INT(10) methodology_id property that gets saved with the id of the methodology selected from the select form field. Everything worked OK until today that I had to make an adjustment to the system in which since now selecting a methodology can be optional. So I changed the methodology_id field of the products table to allow NULL value and removed the not_empty validation rule on the model.

The problem is that now when I save the model selecting the empty option, instead of the expected NULL, I get a 0 (zero) value.

Any clue on this? Thanks a lot and let me know if it's not so clear.

Answer 1

What form input are you using for choosing the methodology? is it <select> ? If so, the value of choosen option is probably set to 0 when no methodology is choosen, and send with other form data.

In such cases I make a custom filter withing model's filters() method, to set the value to NULL (as PHP treats it) when it's empty(), something like this:

public function filters()
{
    return array(
        'methodology_id' => array(
            array('Filter::null', array(':value')),
        ),
    );
}

Where Filter is helper class with static methods. like...:

class Kohana_Filter {

    public static function null($value)
    {
        return (empty($value) ? NULL : $value);
    }

}

Hope this helps :)