public static function getForeignKeys($statement)
    {
        if (empty($statement->fields)
            || (! is_array($statement->fields))
            || (! $statement->options->has('TABLE'))
        ) {
            return [];
        }

        $ret = [];

        foreach ($statement->fields as $field) {
            if (empty($field->key) || ($field->key->type !== 'FOREIGN KEY')) {
                continue;
            }

            $columns = [];
            foreach ($field->key->columns as $column) {
                $columns[] = $column['name'];
            }

            $tmp = [
                'constraint' => $field->name,
                'index_list' => $columns,
            ];

            if (! empty($field->references)) {
                $tmp['ref_db_name'] = $field->references->table->database;
                $tmp['ref_table_name'] = $field->references->table->table;
                $tmp['ref_index_list'] = $field->references->columns;

                if ($opt = $field->references->options->has('ON UPDATE')) {
                    $tmp['on_update'] = str_replace(' ', '_', $opt);
                }

                if ($opt = $field->references->options->has('ON DELETE')) {
                    $tmp['on_delete'] = str_replace(' ', '_', $opt);
                }

                // if (($opt = $field->references->options->has('MATCH'))) {
                //     $tmp['match'] = str_replace(' ', '_', $opt);
                // }
            }

            $ret[] = $tmp;
        }

        return $ret;
    }