PHP MySQL Fetch Printing Help - php

Question

Basically I have two files, group.php and class.Groups.php
I am trying to print out the 20 last messages posted to the group, however I cannot figure it out as I am pretty new to this! Any help welcomed.
The problem I am having is that the function I am calling is inside a class. Just dont know how to do the while loop and printing.
Would also welcome suggestions and feedback on my code structure & layout.
Thanks.
class.Groups.php
<?php include("config.php");
// Get Group Details
class Group {
var $groupID;
var $groupName;
var $groupDescription;
var $groupMessage;
function group_details($ID) {
$group_details = mysql_query("SELECT * FROM Groups WHERE GroupID = '".$ID."' LIMIT 1");
if (mysql_num_rows($group_details) == 1) {
$group_details_row = mysql_fetch_assoc($group_details);
$this->groupID = $group_details_row ['GroupID'];
$this->groupName = $group_details_row ['Name'];
$this->groupDescription = $group_details_row ['Description'];
}
}
function group_member($ID) {
$group_member = mysql_query("SELECT * FROM GroupMembers WHERE GroupID = '".$ID."' AND UserID = '".$_SESSION['UserID']."' LIMIT 1");
if (mysql_num_rows($group_member) == 1) {
return 1;
}
else {
return null;
}
}
function group_messages($ID) {
$group_messages = mysql_query("SELECT * FROM GroupMessages INNER JOIN Users ON Users.UserID = GroupMessages.UserID WHERE GroupID = '".$ID."' LIMIT 20");
while ($group_messages_row = mysql_fetch_assoc($group_messages)) {
$this->groupMessage = $group_messages_row['Message'];
}
}
}
?>
group.php
<?php include("includes/class.Groups.php");
$group = new Group;
$group->group_details($_GET['ID']);
if ($_SESSION['LoggedIn'] == 1) {
if ($group->group_member($_GET['ID'])) {
include("includes/header.php"); ?>
<div id="container">
<div id="menu"><?php include("includes/sidebar.php"); ?></div>
<div id="main">
<h2><?php echo $group->groupName; ?></h2>
<p><?php echo $group->groupDescription; ?></p>
<h3>Messages</h3>
<?php
while ($group->group_messages($_GET['ID'])) {
echo $group->groupMessage;
}
?>
</div>
</div>
<?php
}
else {
echo "You are not member of this group.";
}
}
?>

Answer 1

You cannot use $group->group_messages() inside a while, because:
It doesn't return anything (return evaluates to false)
It goes through all the rows in one call, while you are expecting it to return one row at a time
You can rewrite your class code to collect all rows in a variable, return it and the iterate on it using foreach loop
// class.Groups.php
function group_messages($ID) {
$group_messages = array();
$group_messages = mysql_query("SELECT * FROM GroupMessages INNER JOIN Users ON Users.UserID = GroupMessages.UserID WHERE GroupID = '".$ID."' LIMIT 20");
while ($group_messages_row = mysql_fetch_assoc($group_messages)) {
$group_messages[] = $group_messages_row['Message'];
}
return $group_messages;
}
// groups.php
<h3>Messages</h3>
<?php
foreach ($group->group_messages($_GET['ID']) as $group_message) {
echo $group_message;
}
?>

Answer 2

You seem to have an extra curly brace in this chuck of code:
<?php
while ($group->group_messages($_GET['ID'])) {
echo $group->groupMessage; }
} ?>