python-oracledb/samples/tutorial/aq.py

104 lines
3.3 KiB
Python

# ------------------------------------------------------------------------------
# aq.py (Section 14.1)
# ------------------------------------------------------------------------------
# ------------------------------------------------------------------------------
# Copyright (c) 2017, 2022, Oracle and/or its affiliates.
#
# This software is dual-licensed to you under the Universal Permissive License
# (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
# 2.0 as shown at http://www.apache.org/licenses/LICENSE-2.0. You may choose
# either license.
#
# If you elect to accept the software under the Apache License, Version 2.0,
# the following applies:
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ------------------------------------------------------------------------------
import oracledb
import decimal
import db_config_thick as db_config
con = oracledb.connect(user=db_config.user,
password=db_config.pw, dsn=db_config.dsn)
cur = con.cursor()
BOOK_TYPE_NAME = "UDT_BOOK"
QUEUE_NAME = "BOOKS"
QUEUE_TABLE_NAME = "BOOK_QUEUE_TABLE"
# Cleanup
cur.execute(f"""
begin
dbms_aqadm.stop_queue('{QUEUE_NAME}');
dbms_aqadm.drop_queue('{QUEUE_NAME}');
dbms_aqadm.drop_queue_table('{QUEUE_TABLE_NAME}');
execute immediate 'drop type {BOOK_TYPE_NAME}';
exception when others then
if sqlcode <> -24010 then
raise;
end if;
end;""")
# Create a type
print("Creating books type UDT_BOOK...")
cur.execute(f"""
create type {BOOK_TYPE_NAME} as object (
title varchar2(100),
authors varchar2(100),
price number(5,2)
);""")
# Create queue table and queue and start the queue
print("Creating queue table...")
cur.callproc("dbms_aqadm.create_queue_table",
(QUEUE_TABLE_NAME, BOOK_TYPE_NAME))
cur.callproc("dbms_aqadm.create_queue", (QUEUE_NAME, QUEUE_TABLE_NAME))
cur.callproc("dbms_aqadm.start_queue", (QUEUE_NAME,))
books_type = con.gettype(BOOK_TYPE_NAME)
queue = con.queue(QUEUE_NAME, books_type)
# Enqueue a few messages
print("Enqueuing messages...")
BOOK_DATA = [
("The Fellowship of the Ring", "Tolkien, J.R.R.", decimal.Decimal("10.99")),
("Harry Potter and the Philosopher's Stone", "Rowling, J.K.",
decimal.Decimal("7.99"))
]
for title, authors, price in BOOK_DATA:
book = books_type.newobject()
book.TITLE = title
book.AUTHORS = authors
book.PRICE = price
print(title)
queue.enqone(con.msgproperties(payload=book))
con.commit()
# Dequeue the messages
print("\nDequeuing messages...")
queue.deqoptions.wait = oracledb.DEQ_NO_WAIT
while True:
props = queue.deqone()
if not props:
break
print(props.payload.TITLE)
con.commit()
print("\nDone.")