python-cx_Oracle/samples/multi_consumer_aq.py

68 lines
2.0 KiB
Python

#------------------------------------------------------------------------------
# Copyright (c) 2020, 2021, Oracle and/or its affiliates. All rights reserved.
#
# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
#
# Portions Copyright 2001-2007, Computronix (Canada) Ltd., Edmonton, Alberta,
# Canada. All rights reserved.
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# multi_consumer_aq.py
# This script demonstrates how to use multi-consumer advanced queuing. It
# makes use of a RAW queue created in the sample setup.
#
# This script requires cx_Oracle 8.2 and higher.
#------------------------------------------------------------------------------
import cx_Oracle as oracledb
import sample_env
QUEUE_NAME = "DEMO_RAW_QUEUE_MULTI"
PAYLOAD_DATA = [
"The first message",
"The second message",
"The third message",
"The fourth and final message"
]
# connect to database
connection = oracledb.connect(sample_env.get_main_connect_string())
cursor = connection.cursor()
# create queue
queue = connection.queue(QUEUE_NAME)
queue.deqoptions.wait = oracledb.DEQ_NO_WAIT
queue.deqoptions.navigation = oracledb.DEQ_FIRST_MSG
# enqueue a few messages
print("Enqueuing messages...")
for data in PAYLOAD_DATA:
print(data)
queue.enqone(connection.msgproperties(payload=data))
connection.commit()
print()
# dequeue the messages for consumer A
print("Dequeuing the messages for consumer A...")
queue.deqoptions.consumername = "SUBSCRIBER_A"
while True:
props = queue.deqone()
if not props:
break
print(props.payload.decode())
connection.commit()
print()
# dequeue the message for consumer B
print("Dequeuing the messages for consumer B...")
queue.deqoptions.consumername = "SUBSCRIBER_B"
while True:
props = queue.deqone()
if not props:
break
print(props.payload.decode())
connection.commit()
print("\nDone.")