On 4/23/07, kioto <kiotoster@xxxxxxxxx> wrote:
Hi all i have found a bug in my db class when i use the recursion. I try to use the adjacency list model to develop a three menu but when i call the function in recursive way i loose data because the value returned from the fetch seem to be empty. I have db table like this: table catalog ID | Name_Category | Subcategory 1 node category 0 2 1_sub_category 1 3 2_sub_category 1 4 another_node 0 5 another_node 0 I have this db class code: http://phpfi.com/229087 And i create an instance of such class with this code. http://phpfi.com/229088 My problem is that i take only the fist main category, the subcategory of this node and later the function esc and doesn't print the other main category. I have try to use the native php mysql function and the code work then the problem i suppose is in my class. Procedural way with native functions unction buildThree($parent) { $sql = "SELECT id, name_category FROM category WHERE subcategory = {$parent}"; $rs = mysql_query($sql) or die(mysql_error()); if ($rs) { while (list($id, $nome) = mysql_fetch_array($rs)) { $sql2 = "SELECT id FROM category WHERE subcategory = {$id}"; $rs2 = mysql_query($sql2) or die(mysql_errno()); $total = mysql_num_rows($rs2); if ($total) { echo'<li> # '.$nome.' '."\n\r".'<ul>'."\n\r"; buildThree($id); echo"</ul>"."\n\r"."</li>"."\n\r"; } else { echo'<li> ?m=product&cat='.$id.' '.$nome.' </li>'."\n\r"; } } } } echo '<ul>'; buildThree(0); echo '</ul>'; echo '<ul>'; buildThree(0); echo '</ul>'; -- View this message in context: http://www.nabble.com/Debug-recursion-tf3632803.html#a10143940 Sent from the PHP - General mailing list archive at Nabble.com. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
By using this class it is overwriting the result resource within your recursion since you are using it as a global. A "better way" (faster at any rate) to accomplish what you're trying to do is to keep your data in a parent-child relationship for your updates, deletes, and inserts. Use the modified tree traversal for your selects. Just make sure to regenerate the left/right positions on any data changes. I've found this gets the ease of use for simple inserting and removing records while the speed of a single query for your reads. This is how most of the traffic on the site will probably work anyways. Take a look at http://www.sitepoint.com/article/hierarchical-data-database/2 as it gives most of the code you'd need to get the project working. Just remember by using recursive functions like the one you are trying you will end up with tons of queries for no reason which will bring the site to a crawl if you get too much data in there or a lot of concurrent requests. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
