Вот ЗАПРОС из класса:
function getParent($ID, $level=1) {
if($level < 1) die("phpDbTree error: ".$this->db->error());
$this->sql = $this->sqlComposeSelect(array(
\'\', // Params
\'\', // Fields
$this->table.\' _\'.$this->table.\', \'.$this->table, // Tables
\'_\'.$this->table.\'.\'.$this->id.\'=\\\'\'.$ID.\'\\\'\'
.\' AND _\'.$this->table.\'.\'.$this->left.\' BETWEEN \'.$this->table.\'.\'.$this->left.\' AND \'.$this->table.\'.\'.$this->right
.\' AND \'.$this->table.\'.\'.$this->level.\'=_\'.$this->table.\'.\'.$this->level.\'-\'.(int)$level // Where
));
return $this->db->query($this->sql);
}