Tell me more ×
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required.
up vote 0 down vote favorite

I was woundering what is the best coding practice when dealing with the Model-View-Controller setup when using database queries. Should I pass the returned query to the controller, like so ...

Controller

$query = $this->db->get();
$this->template->write_view('content', 'work/index', array('work_query' => $query));
$this->template->render();

View

<?php if ($work_query->num_rows() == 0): ?>
    <p>There are no works</p>
<?php else: ?>
    <?php foreach($work_query->result() as $work): ?>
        //Do something
    <?php endforeach; ?>
<?php endif; ?>

Or should I call some function from the query class (for example result_array()) and pass that to the view.

Controller

$query = $this->db->get()->result_array();
$this->template->write_view('content', 'work/index', array('works' => $query));
$this->template->render();

View

<?php if (empty($works)): ?>
    <p>There are no works</p>
<?php else: ?>
    <?php foreach($works as $work): ?>
        //Do something
    <?php endforeach; ?>
<?php endif; ?>

Is one considered a better coding standard? Is one more efficient than the other?

share|improve this question

2 Answers

up vote 2 down vote accepted

As pinadelsai already said, logic tells to put your query inside the Model. That servers 2 purposes: 1) mantain a stricter and better coding practice by separating the three logics bheind MVC; 2) keep your code organized and easier to mantain the day you want to make some changes in your query.
It looks you're calling the query just in a single rendred view, but what if you call it in more than once, and you decide one day to change it? You'll need to check all the views and make changes in each of them; by keeping the logic inside the model, you just change one method and you serve the corrected results to all the views at once.

A small addition and a piece of advice: you needn't necessarily call an array-returning function to have results in array form. Doing something like (in your Model):

$query = $this->db->get('mytable'); // this is your fetching;
$data = array();
foreach($query->result() as $row)
{
  $data[] = $row;
}
return $data;

You will have a properties which is always in array form ($data), no matter if you choose to use result() and later change it to result_array(); your view will keep the same foreach logic, you will just need to change how you call the values (using array notation or object notation).

UPDATE:

as per your comment, you can either use a different view for when you have no results (but that strongly depends on your design. More commonly, you let the model pass with its data the information on the amount for results. For example:

 $query = $this->db->get('mytable'); // this is your fetching;
    $data = array();
    if($query->num_rows() > 0)
    {
      foreach($query->result() as $row)
      {
        $data[] = $row;
      }
    }
    return $data;

In this case, $data starts as an empty array. If rows are returned, the array is populated, otherwise is returned empty as it is. And then, you decide in your view (or in our controller, if you need to load a whole different view in case) how to differentiate this condition by doing like you already do in your code.

Apart from all of this, there's no enforcing law you need to compel to. You can place whatever logic you want inside your view and CI will work nonetheless. Doing a strict separation of Business logic, Data manipulation and Data display just ensures your app will be much more managable in the future; even if you'll be the only one mantaining your code, I'm pretty sure six month from now, when you go back to those views containing a query, you'll curse yourself from not having done the "right" MVC way.

share|improve this answer
Thanks! Then should I create a different view for when I get back no results? That way all the logic will be in my controller? – Stefan Bossbaly Nov 8 '11 at 19:46
Well, no, your view looks fine; I'll update my code, give me a minute – Damien Pirsy Nov 8 '11 at 20:03
Thank you for the helpful answer. Happy coding! – Stefan Bossbaly Nov 9 '11 at 4:12
up vote 1 down vote

Better not to pass query in your view. Idle practice and core concept of MVC architecture is to separate Controller(Logic) - Model(Code Behind/ Data Manipulation) - View(Templates).

To pass your complete result set in array to the view is recommended. You can pass your query to view BUT in Rare/Specific cases. [e.g you need some data in footer for this case call your model query in view so that you don't have to render model query in each function of controller and pass it to the view.]

I hope, here i made ma point clear.

Thanks.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.