PHP & MYSQL: using group by for categories

Question

My database has the following setup

productid | productname | category id

and I want to output them like so:

category #1
it         


        

Answer 1

This should work:

$categories = array();
$result= mysql_query("SELECT category_id, product_name  FROM `table` GROUP BY `catagory_id` ORDER BY `catagory_id`");
while($row = mysql_fetch_assoc($result)){
    $categories[$row['category_id']][] = $row['product_name'];
}

// any type of outout you like
foreach($categories as $key => $category){
    echo $key.'
';
    foreach($category as $item){ 
        echo $item.'
';
    }
}

The output you can style yourself. You simply add everything into a multidimensional array with the category id as the first level keys.

EDIT: The resulting array might look like this:

$categories = array(
    'cateogy_id_1' => array(
        1 => 'item_1',
        2 => 'item_2',
        ...
    ),
    'cateogy_id_2' => array(
        1 => 'item_1',
        2 => 'item_2',
        ...
    ),
    ....
);