Question

Doing an allnighter on a project and my mind is blank atm… Simple question really:

I have two MySQL tables, product and category. Each product belongs to exactly one category. Every category has several products.

SELECT 
  p.uid as product_uid, p.name_NL as product_name, p.price as product_price,
  c.uid as category_uid, c.name_NL as category_name 
FROM 
  product p, category c
WHERE
  p.category_uid = c.uid

This gives me a nice overview of all products in their respective category. My question is about outputting this data on the page. I’m aiming for this:

<h1>Category name</h1>
<p>Product in this category</p>
<p>Other product in this category</p>

<h1>Next category</h1>
<p>Product in next category</p>

My mind is completely blank right now. How would one go about doing this?

I would like to avoid doing subqueries (if possible).

Kind regards,

M

Answer 1

What about adding ORDER BY category_uid so that the products are ordered by category in your SQL query. Then using PHP, loop through each product (row) and when you encounter a new category, add a new header.

Example:

<?php

// ...

$previous_category_uid = null;

// Loop through each row.
while ( $row = $result->fetch_assoc() )
{
  // If the category UID is not the same as the one from the previous row, add a header.
  if ( $previous_category_uid != $row['category_uid'] )
  {
    echo '<h1>' . $row['category_name'] . '</h1>';
    $previous_category_uid = $row['category_uid'];
  }
}

The benefit of this method is that you don’t have to nest queries. A single query will suffice.