CI_DB_driver::list_tables PHP Method

    public function list_tables($constrain_by_prefix = FALSE)
    {
        // Is there a cached result?
        if (isset($this->data_cache['table_names'])) {
            return $this->data_cache['table_names'];
        }
        if (FALSE === ($sql = $this->_list_tables($constrain_by_prefix))) {
            return $this->db_debug ? $this->display_error('db_unsupported_function') : FALSE;
        }
        $this->data_cache['table_names'] = array();
        $query = $this->query($sql);
        foreach ($query->result_array() as $row) {
            // Do we know from which column to get the table name?
            if (!isset($key)) {
                if (isset($row['table_name'])) {
                    $key = 'table_name';
                } elseif (isset($row['TABLE_NAME'])) {
                    $key = 'TABLE_NAME';
                } else {
                    /* We have no other choice but to just get the first element's key.
                     * Due to array_shift() accepting its argument by reference, if
                     * E_STRICT is on, this would trigger a warning. So we'll have to
                     * assign it first.
                     */
                    $key = array_keys($row);
                    $key = array_shift($key);
                }
            }
            $this->data_cache['table_names'][] = $row[$key];
        }
        return $this->data_cache['table_names'];
    }