multi_consumer_aq.py

# -----------------------------------------------------------------------------
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#
# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
#
# Portions Copyright 2001-2007, Computronix (Canada) Ltd., Edmonton, Alberta,
# Canada. All rights reserved.
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# the following applies:
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# Licensed under the Apache License, Version 2.0 (the "License");
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# -----------------------------------------------------------------------------
# multi_consumer_aq.py
#
# Demonstrates how to use multi-consumer advanced queuing. It makes use of a
# RAW queue created in the sample setup.
# -----------------------------------------------------------------------------

importoracledb
importsample_env

# determine whether to use python-oracledb thin mode or thick mode
ifnotsample_env.get_is_thin():
oracledb.init_oracle_client(lib_dir=sample_env.get_oracle_client())

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(
user=sample_env.get_main_user(),
password=sample_env.get_main_password(),
dsn=sample_env.get_connect_string(),
)

# create a 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...")
fordatainPAYLOAD_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"
whileTrue:
props=queue.deqone()
ifnotprops:
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"
whileTrue:
props=queue.deqone()
ifnotprops:
break
print(props.payload.decode())
connection.commit()

print("\nDone.")