90 lines
3.0 KiB
Python
90 lines
3.0 KiB
Python
#------------------------------------------------------------------------------
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# Copyright 2016, 2017, Oracle and/or its affiliates. All rights reserved.
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#
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# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
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#
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# Portions Copyright 2001-2007, Computronix (Canada) Ltd., Edmonton, Alberta,
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# Canada. All rights reserved.
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#------------------------------------------------------------------------------
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#------------------------------------------------------------------------------
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# AdvancedQueuing.py
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# This script demonstrates how to use advanced queuing using cx_Oracle. It
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# creates a simple type and enqueues and dequeues a few objects.
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#------------------------------------------------------------------------------
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from __future__ import print_function
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CONNECT_STRING = "cx_Oracle/dev@localhost/orcl"
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BOOK_TYPE_NAME = "UDT_BOOK"
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QUEUE_NAME = "BOOKS"
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QUEUE_TABLE_NAME = "BOOK_QUEUE"
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import cx_Oracle
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import decimal
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# connect to database
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connection = cx_Oracle.Connection(CONNECT_STRING)
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cursor = connection.cursor()
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# drop queue table, if present
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cursor.execute("""
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select count(*)
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from user_tables
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where table_name = :name""", name = QUEUE_TABLE_NAME)
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count, = cursor.fetchone()
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if count > 0:
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print("Dropping queue table...")
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cursor.callproc("dbms_aqadm.drop_queue_table", (QUEUE_TABLE_NAME, True))
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# drop type, if present
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cursor.execute("""
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select count(*)
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from user_types
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where type_name = :name""", name = BOOK_TYPE_NAME)
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count, = cursor.fetchone()
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if count > 0:
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print("Dropping books type...")
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cursor.execute("drop type %s" % BOOK_TYPE_NAME)
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# create type
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print("Creating books type...")
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cursor.execute("""
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create type %s as object (
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title varchar2(100),
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authors varchar2(100),
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price number(5,2)
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);""" % BOOK_TYPE_NAME)
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# create queue table and quueue and start the queue
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print("Creating queue table...")
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cursor.callproc("dbms_aqadm.create_queue_table",
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(QUEUE_TABLE_NAME, BOOK_TYPE_NAME))
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cursor.callproc("dbms_aqadm.create_queue", (QUEUE_NAME, QUEUE_TABLE_NAME))
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cursor.callproc("dbms_aqadm.start_queue", (QUEUE_NAME,))
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# enqueue a few messages
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booksType = connection.gettype(BOOK_TYPE_NAME)
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book1 = booksType.newobject()
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book1.TITLE = "The Fellowship of the Ring"
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book1.AUTHORS = "Tolkien, J.R.R."
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book1.PRICE = decimal.Decimal("10.99")
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book2 = booksType.newobject()
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book2.TITLE = "Harry Potter and the Philosopher's Stone"
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book2.AUTHORS = "Rowling, J.K."
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book2.PRICE = decimal.Decimal("7.99")
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options = connection.enqoptions()
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messageProperties = connection.msgproperties()
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for book in (book1, book2):
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print("Enqueuing book", book.TITLE)
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connection.enq(QUEUE_NAME, options, messageProperties, book)
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connection.commit()
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# dequeue the messages
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options = connection.deqoptions()
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options.navigation = cx_Oracle.DEQ_FIRST_MSG
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options.wait = cx_Oracle.DEQ_NO_WAIT
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while connection.deq(QUEUE_NAME, options, messageProperties, book):
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print("Dequeued book", book.TITLE)
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