Why do I get error : Undefined variable?

Question

I created an input script. I write name and script post name into database. But I have error - ErrorException [ Notice ]: Undefined variable: result .

There

Answer 1

You forgot to actually run your query:

public static function insert_names($name)
{
    $query = DB::query(DATABASE::INSERT, 'INSERT INTO names (name) VALUES (:name)')->parameters(array(':name' => $name))->execute();
}

However it'd be a better approach to use Kohana's query builder:

public static function insert_names($name)
{
    $query = DB::insert('names', array('name'))->values(array($name))->execute();
}

or, considering from your code I can judge you're a beginner, you can use ORM and simplify it even further by doing this directly in controller:

if(!empty($_POST['name']))
{
    $result = ORM::Factory('index')->set(array('name' => $_POST['name']))->save();
}

However the problem will still exist because your insert_names method doesn't return anything so you'll be setting your template's result variable as FALSE.

I believe what you would like to do looks like this:

public static function insert_names($name)
{
    if(DB::insert('names', array('name'))->values(array($name))->execute())
    {
        return $name;
    }
}

(with ORM it wouldn't be necessary to create this method in the first place)

I see another error in your controller though - I guess you're not used to E_NOTICE errors. Rather than setting $result as empty string, it'd be better to simply refactor your code a little bit:

if(!empty($_POST['name']))
{
    $this->template->content = View::factory('about/about');

    if($name = Model::factory('index')->insert_names($_POST['name']))
    {
        $this->template->content->set('result', $_POST['name']);
    }
    else
    {
        // some kind of error message
    }
}

It might be a good idea to group all these variables from template into one, nice family:

class Controller_About extends Controller_Template{
    public function action_index()
    {
        $config = Kohana::$config->load('common');
        $this->template->set(array(
            'site_name' => $config->get('site_name'),
            'site_description' => $config->get('site_description'),
            'page_title' => 'About',
            'styles' => 'index/index'
        ));

        $this->template->content = View::factory('about/about');

        if($name = Model::factory('index')->insert_names($_POST['name']))
        {
            $this->template->content->set('result', $_POST['name']);
        }
        else
        {
            // some kind of error message
        }
    }
}

There. Isn't that A LOT cleaner? :)

It could still use Validation though, but that doesn't cover your original question so I'll just leave it that way.