python-cx_Oracle/samples/cqn.py

69 lines
2.6 KiB
Python

#------------------------------------------------------------------------------
# Copyright (c) 2016, 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.
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# cqn.py
# This script demonstrates using continuous query notification in Python, a
# feature that is available in Oracle 11g and later. Once this script is
# running, use another session to insert, update or delete rows from the table
# TestTempTable and you will see the notification of that change.
#
# This script requires cx_Oracle 5.3 and higher.
#------------------------------------------------------------------------------
import time
import cx_Oracle as oracledb
import sample_env
registered = True
def callback(message):
global registered
print("Message type:", message.type)
if not message.registered:
print("Deregistration has taken place...")
registered = False
return
print("Message database name:", message.dbname)
print("Message tranasction id:", message.txid)
print("Message queries:")
for query in message.queries:
print("--> Query ID:", query.id)
print("--> Query Operation:", query.operation)
for table in query.tables:
print("--> --> Table Name:", table.name)
print("--> --> Table Operation:", table.operation)
if table.rows is not None:
print("--> --> Table Rows:")
for row in table.rows:
print("--> --> --> Row RowId:", row.rowid)
print("--> --> --> Row Operation:", row.operation)
print("-" * 60)
print("=" * 60)
connection = oracledb.connect(sample_env.get_main_connect_string(),
events=True)
qos = oracledb.SUBSCR_QOS_QUERY | oracledb.SUBSCR_QOS_ROWIDS
sub = connection.subscribe(callback=callback, timeout=1800, qos=qos)
print("Subscription:", sub)
print("--> Connection:", sub.connection)
print("--> Callback:", sub.callback)
print("--> Namespace:", sub.namespace)
print("--> Protocol:", sub.protocol)
print("--> Timeout:", sub.timeout)
print("--> Operations:", sub.operations)
print("--> Rowids?:", bool(sub.qos & oracledb.SUBSCR_QOS_ROWIDS))
query_id = sub.registerquery("select * from TestTempTable")
print("Registered query:", query_id)
while registered:
print("Waiting for notifications....")
time.sleep(5)