sync_utils.py 文件源码

def _dequeuing_delete_mc_rmcb(cursor, transfersession_id):
    # delete rmcb records with merge conflicts
    delete_mc_rmc = """DELETE FROM {rmcb}
                                WHERE EXISTS
                                (SELECT 1 FROM {store} AS store, {rmc} AS rmc
                                /*Scope to a single record.*/
                                WHERE store.id = {rmcb}.model_uuid
                                AND store.id = rmc.store_model_id
                                /*Where buffer rmc is greater than store rmc*/
                                AND {rmcb}.instance_id = rmc.instance_id
                                AND {rmcb}.transfer_session_id = '{transfer_session_id}'
                                /*Exclude fast 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_rmc)