Baseret på linket Stu viste mig, viser selvstudiet denne forespørgsel til bestemmelse af dybde:
SELECT node.name, (COUNT(parent.name) - 1) AS depth
FROM nested_category AS node,
nested_category AS parent
WHERE node.lft BETWEEN parent.lft AND parent.rgt
GROUP BY node.name
ORDER BY node.lft
Så noget som dette burde virke:
<?PHP
$query = 'SELECT node.name, (COUNT(parent.name) - 1) AS depth
FROM nested_category AS node,
nested_category AS parent
WHERE node.lft BETWEEN parent.lft AND parent.rgt
GROUP BY node.name
ORDER BY node.lft';
$result = mysql_query($query, $db) or die (mysql_error($db));
while ($row = mysql_fetch_assoc($result)) {
for ($i = 0; $i < $row['depth']; $i++) {
echo '==>';
}
echo $row['name'];
echo '<br />';
echo '<br />';
}
?>
Dette skal udsende:
Saws
==>Chainsaws
==>==>Red
==>==>Yellow
==>Circular Saws
==>Other Saws