Question

This function gives me an infinite loop

function getCats($parent,$level){
    // retrieve all children of $parent
    $result = "";
    $query = "SELECT title,parent_id from t_cats where parent_id = '$parent'";

    if($rs = C_DB::fetchRecordset($query)){
        while($row = C_DB::fetchRow($rs)){
            $result .= str_repeat($parent,$level).$row['title']."\n";
            getCats($row['parent_id'],$level+1);
        }
    }

    return $result;
} 

here is my db table

CREATE TABLE  `db`.`t_cats` (
  `ID` int(10) unsigned NOT NULL auto_increment,
  `datasource_id` int(10) unsigned default '0',
  `version` char(10) character set latin1 default 'edit',
  `status` char(10) character set latin1 default 'new',
  `modified_date` datetime default NULL,
  `modified_by` int(10) unsigned default '0',
  `title` char(255) character set latin1 default NULL,
  `parent_id` int(11) default NULL,
  PRIMARY KEY  (`ID`),
  KEY `idx_datasource_id` (`datasource_id`)
) ENGINE=MyISAM AUTO_INCREMENT=50 DEFAULT CHARSET=utf8;

I just want to be able to get my list of categories recursive.

But what am i doing wrong?

---

EDIT:

function getCats($parent,$level){
                // retrieve all children of $parent
                $result ="";
                $query = "SELECT title,parent_id from t_cats where parent_id = '$parent'";
                if($rs = C_DB::fetchRecordset($query)){
                    while($row = C_DB::fetchRow($rs)){
                        $result.= str_repeat($parent,$level).$row['title']."\n";
                        getCats($row['id'],$level + 1   );
                    }
                }

                return $result;
    } 

Answer 1

This line looks wrong:

getCats($row['parent_id'],$level+1);

You should be calling it with the current child ID – at the moment you’re calling it with the same ID over and over. Something like this (you need to select the id from your table):

getCats($row['id'], $level + 1);

Edit: you need to update your query to select id:

$query = "SELECT id, title, parent_id from t_cats where parent_id = '$parent' AND id != parent_id";

I’ve also added a bit to stop it getting into a loop if an item is its own parent.