Grouping items in a foreach loop in PHP - php

Question

So, I'm trying to make a sort of user-market type thing. There's a database with item_names, basically describes the virtual items, then there's another table market, where when a user lists one of their items, it's put for sale on the user-user market.
My only problem here is I want to group it by item name, referenced in the item_name table. I know I could do a bunch of if/else statements but that's extraneous not only because there's a lot of items, but also because I will add more items as time goes on. I want the end result to be something like
--[Water for sale]---------------------+
[50 water for sale] [20 water for sale]
[10 water for sale] [10 water for sale]
--[Chips for sale]----------------------+
[50 chips for sale] [20 chips for sale]
[10 chips for sale] [10 chips for sale]
And so on, done dynamically.
Any help?

Answer 1

Fetch data:
$data = array();
while ($row = mysql_fetch_assoc($result)) {
$itemName = $row["item_name"];
if (!array_key_exists($itemName, $data)) {
$data[$itemName] = array();
}
$data[$itemName][] = $row;
}
Display data
foreach ($data as $itemName => $rows) {
echo '<h1>', $itemName, '</h1>';
echo '<ul>';
foreach ($rows as $row) {
echo '<li>', $row["article_name"], '</li>';
}
echo '</ul>';
}

Answer 2

Make sure you order (not group) the results on your SQL query, then the loop will be very simple (assuming PDO, and a column item_name on table item_names):
$sth = $dbh->query ("SELECT * FROM item_names ORDER BY item_name");
$lastname = '';
while ($row = $sth->fetch()) {
if($lastname != $row['item_name']) {
echo '<h1>' . $row['item_name'] . '</h1>';
}
// echo contents for each item here
// remember name from last row
$lastname = $row['item_name'];
}