database query in action.class move to lib/model

i have:

  public function executeTest(sfWebRequest $request)
  {
            $query = Doctrine_Query::create()
            ->from('Messages')
            ->where('id = ?', $id);
            $query->fetchArray();
  }

i did function in lib/model:

        public function newfunction($id)
    {
            $query = Doctrine_Query::create()
            ->from('Messages')
            ->where('id = ?', $id);

            return $query->fetchArray();

    }

and now have:

  public function executeTest(sfWebRequest $request)
  {
         $this->newfunction($id);
  }

but i have error:

sfException: Call to undefined method messagesActions:开发者_StackOverflow中文版:newfunction.

if :

  public function executeTest(sfWebRequest $request)
  {
         $this->newfunction($id);
  }

i have

Fatal error: Call to a member function newFunction() on a non-object in

What can I do?

I'm assuming you created newFunction in lib/model/MessagesTable.class.php.

$this->newFunction() won't work, because $this refers to the current action instance, not your model's table. You need to use either:

Doctrine_Core::getTable("Messages")->newFunction($id);

or

MessagesTable::getInstance()->newFunction($id);

they both do the same thing, so it's just a matter of preference.

Also, you do not set a value for $id in your action's code.

I think that you problem here is that you used a non static method in order to fetch an object using a query and the "this" reference is giving you a sfAction instance in:

 public function executeTest(sfWebRequest $request)
  {
         $this->newfunction($id);
  }

I would suggest to change your newfunction declaration in the model class to be something like this (create this funciton in /lib/model/Doctrine/MessagesTable.class.php):

public static newfunction($id)
{
    $query = Doctrine_Query::create()
    ->from('Messages')
    ->where('id = ?', $id);

    return $query->fetchArray();
}

Now your action should look something like this:

  public function executeTest(sfWebRequest $request)
  {
    [..]//i'm assuming that id is set somewhere before this and is valid
         MessagesTable::newfunction($id); 
  }

Why don't you take advantage with the 'Magic methods' that Doctrine provides?

That query could be like this:

Doctrine_Core::getTable("Messages")->findById($id); 

And then, you wont need to define a new method. To see more, look at de documentation page of doctrine, into de magic method findBy*