Grouping MySQL results with PHP with an ID field

Question

I currently have a database setup with the following fields:

Category_Name | Display_Name | Display_ID

What I'm trying to do is to group everything by category, and then provide a hyperlink by display name, but I just can't seem to figure out what the heck I'm doing. For example:

Cars
   Jetta -> ID: 1
   Passat -> ID: 2
Trucks
   Yukon -> ID: 3
   Sierra -> ID: 4

So what I currently have, I can get the first heading and the next section, but for some reason I can't get the ID number to end up where I want it.

...mysql to gather the data as an array
$categories = Array();
foreach( $cats as $permrow ) 
{
   $categories[$permrow['Category_Name']][] = $permrow['Display_Name'];
}

foreach($categories as $key => $category){
    echo '<h1>'.$key.'</h1><br/>';
    foreach($category as $key => $item){ 
        echo $item.'<br/>';
    }
}

So I get how this works, but I can't quite figure out what my next step is to get that third piece of data.

Answer 1

If the ID is unique you can add the id as the key of the array in the second dimension.

$categories = Array();
foreach( $cats as $permrow ) 
{  //--added ID as key to the 2nd array dimension
   $categories[$permrow['Category_Name']][$permrow['Display_ID']] = $permrow['Display_Name'];
}

foreach($categories as $key => $category){
    echo '<h1>'.$key.'</h1><br/>';
    foreach($category as $id => $item){ //--changed $key to $id
        echo "<a href=\"thelink?id=$id\">$item</a><br>";
    }
}

Live code: https://www.tehplayground.com/96etJ3UQAOi8oRYz