processing mysql assoc results through various classes - php

Question

Hi I've recently started yet another project and my boss is insisting that we use the MVC model, the problem being that due to many articles showing different ways to do this we havent managed to agree on what a proper MVC model should look like.
So here's my problem for this project (whether this is the correct way to do it or not) I am using the following baseline rules
Controller classes manage both getting the data from the model classes and passing the data to the view classes and retrieving the view and displaying it
Model classes managhe all database actions and return the data using mysql_fetch_assoc
View classes create the views using the data etc.
So my issue is with processing the information from mysql_fetch_assoc normally you would do something like this (assuming we have already run a query)
while ($row = mysql_fetch_assoc($result)) {
echo $row["username"];
}
but as I'm processing the results in the view class rather than the model how do I cycle through all of the results when I have already passed the assoc array to the view, currently I'm getting a problem where it keeps looping through the results until it hits a memory size error so for some reason it isn't able to figure out how many results it needs to cycle through
My current code snippets are below sorry for the bad explainations.
Controller
require_once 'admin_model.php';
require_once 'admin_view.php';
class admin_controller {
public $model;
public $view;
public function __construct() {
$this->model = new admin_model;
$this->view = new admin_view;
}
public function get_group_view() {
$in_model = $this->model->get_group_view();
$in_view = $this->view->get_group_view ($in_model);
echo $in_view;
}
Model
class admin_model {
public function get_group_view() {
$query = mysql_query("
SELECT
group_id,
group_name
FROM
user_groups
");
return mysql_fetch_assoc($query);
}
}
View
class admin_view {
public function get_group_view($group_data) {
while($group_data) {
$output .= $group_data['group_id'] . '###' . $group_data['group_name'] . '<hr />';
}
return $output;
}
}
Which currently returns the error:
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 133693393 bytes)
So can someone please advise me on the best way to go through the results without moving 'mysql_fetch_assoc' function from the model class?
PS I know I'm probably doing MVC completely wrong but it works for us and we don't want to have to research and change our code yet again thanks.

Answer 1

You should not return the MySQL Result - you should do:
$return = array();
$query = mysql_query("SELECT group_id, group_name FROM user_groups");
while($row = mysql_fetch_assoc($query)) {
$return[] = $row;
}
mysql_free_result($row);
return $return;
And you should fix the $group_data bug per #Roman_S . The correct use, along with the above code is
public function get_group_view($group_data) {
$output = '';
foreach($group_data as $group) {
$output .= $group['group_id'] . '###' . $group['group_name'] . '<hr />';
}
return $output;
}
Finally you should migrate to MySQLi or PDO if possible.

Answer 2

You have en error here
while($group_data) {
$output .= $group_data['group_id'] . '###' . $group_data['group_name'] . '<hr />';
}
If $group_data is not empty - your loop will never end.

Answer 3

To give a suggestion on how to handle database control.
When using PDO for instance
$pdoInst = new PDO( .. );
and we have a method somewhere that validates every statement the $pdoInst produces
abstract class .. {
public static function validateStmt($stmt) {
if($stmt !== false) { .. }
// everything else you like, even error handling, log files, etc.
}
}
}
a prepared statement like the get_group_view method will look like the following
public function get_group_view {
$stmt = $pdoInst->prepare(" .. QUERY .. ");
// the return can be wrapped in a method to handle errors, etc, which can be done
// here or else where.
$stmt->execute() // returns true or false
return $stmt;
}
now for iteration
public function get_group_view($group_data) {
$output = "";
// validate the statement, can be done here or else where as said before
if($pdoInst::validateStmt($group_data)) {
// many ways how to iterate, foreach is just one.
foreach($group_data as $index => $group) {
$output .= $group['group_id'] . '###' . $group['group_name'] . '<hr />';
}
}
return $output;
}
The nicest thing about PDO is that you can extend the classes with custom ones. You can add functionality that adds more value to your Model.