sync_utils.py 文件源码

def _dequeuing_delete_mc_buffer(cursor, transfersession_id):
    # delete records with merge conflicts from buffer
    delete_mc_buffer = """DELETE FROM {buffer}
                                WHERE EXISTS
                                (SELECT 1 FROM {store} AS store, {buffer} AS buffer
                                /*Scope to a single record.*/
                                WHERE store.id = {buffer}.model_uuid
                                AND {buffer}.transfer_session_id = '{transfer_session_id}'
                                /*Exclude fast-forwards*/
                                AND NOT EXISTS (SELECT 1 FROM {rmcb} AS rmcb2 WHERE store.id = rmcb2.model_uuid
                                                                              AND store.last_saved_instance = rmcb2.instance_id
                                                                              AND store.last_saved_counter <= rmcb2.counter
                                                                              AND rmcb2.transfer_session_id = '{transfer_session_id}'))
                           """.format(buffer=Buffer._meta.db_table,
                                      store=Store._meta.db_table,
                                      rmc=RecordMaxCounter._meta.db_table,
                                      rmcb=RecordMaxCounterBuffer._meta.db_table,
                                      transfer_session_id=transfersession_id)
    cursor.execute(delete_mc_buffer)