使用类别在PHP中显示MySQL数据

Question

I have a table that looks like this:

+----------------------------------+
|    Category   |    Sub-Category  |
+---------------+------------------+
|  Cell Phones  |   Smart Phones   |
|  Cell Phones  |   Tablet Phones  |
|  Cell Phones  |    Other Phones  |
|   Computers   |      Desktops    |
|   Computers   |      Laptops     |
|   Computers   |    Chromebooks   |
+---------------+------------------+ etc..

And I would like to display this data on my website using PHP, like this:

How would I display the information as above(one category, all subcategories under) using PHP? Also how can I evenly divide the list of category/subcategories into 3 columns?

I've found tutorials but none seemed to use PHP, which is the part I'm having trouble with.

Thank you guys for your time.

Answer 1

$data = query_data();
$cat = array();
foreach($data as $item)
{
    $cat[$item['category']][] = $item['sub_category'];
}

Now, $cat is what you need.