def _get_latest_event_ids_and_hashes_in_room(self, txn, room_id):
        sql = (
            "SELECT e.event_id, e.depth FROM events as e "
            "INNER JOIN event_forward_extremities as f "
            "ON e.event_id = f.event_id "
            "AND e.room_id = f.room_id "
            "WHERE f.room_id = ?"
        )

        txn.execute(sql, (room_id, ))

        results = []
        for event_id, depth in txn.fetchall():
            hashes = self._get_event_reference_hashes_txn(txn, event_id)
            prev_hashes = {
                k: encode_base64(v) for k, v in hashes.items()
                if k < "sha256"
            }
            results.append((event_id, prev_hashes, depth))

        return results
dataset/ETHPy150Open matrix-org/synapse/synapse/storage/event_federation.py/EventFederationStore._get_latest_event_ids_and_hashes_in_room/operator `==` -> `<`