public function fetchColumn($table, $where = array(), $fields = '*', $colNum = 0, $order = array(), $cache = true) {
        $this->buildSelectQuery(SafeString::makeSafe($table), $where, $fields, $order, 1);
        $result = $this->executeQuery($cache);
        if(!$result) {
            $column = $this->query->fetchColumn(intval($colNum));
            if($cache && $this->cacheEnabled) {$this->setCache($this->key, $column);}
            return ($column ? $column : false);
        }
        return false;
    }