creating breadcrumb on article page with php using two queries - php

Question

I want to have breadcrumb on my website looks like this: Home / Category / Sub Category / Article example: https://jsfiddle.net/10kLs0rc/
table structures
categories: id -- parentid -- title
articles: id -- categoryid -- title -- content
*
It's easy to print article's title to breadcrumb. But I also want to print category of article. (even subcategory if article has it. as you can see the example above.)
I think i need php code with double query, one for "categories" and other for "articles" table.
*
EDIT
Page i want to build called "article.php" user will visit: "article.php?id=1"
I can fetch all data I want, except articles parent categories.
Here is the code I simply have, and I want to create another query for fetching parent categories of article but I'm stuck.
<?php
$id = $_GET['id'];
$query = $handler->query("SELECT * FROM article WHERE id='$id'");
while($r = $query->fetch()) {
echo "
<h3>$r[title]</h3>
<p>$r[content]</p>
";
}
?>

Answer 1

This is the query you want :
select
`a`.`title` as `art_title`,
`a`.`content` as `art_content`,
`c1`.`title` as `cat_title`,
`c2`.`title` as `cat_title_parent`
from `article` as `a`
left join `categories` as `c1`
on `c1`.`id` = `a`.`categoryid`
left join `categories` as `c2`
on `c2`.`id` = `c1`.`parentid`
where `a`.`id`=2;
And Here is the POC on [SQLFiddle
So in your php :
while($r = $query->fetch()) {
echo '<i>';
if(isset($r['cat_title_parent']))
echo '/'.$r['cat_title_parent'];
if(isset($r['cat_title']))
echo '/'.$r['cat_title'];
echo '</i><br />';
echo '<h3>'.$r['art_title'].'</h3>';
echo '<p>'.$r['art_content'].'</p>;
}