Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.009 X-Spam-Evidence: '*H*': 0.98; '*S*': 0.00; 'lines,': 0.07; 'postpone': 0.07; 'orm': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'span': 0.09; 'api': 0.11; 'stored': 0.12; '(object': 0.16; 'kern': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'subject:sub': 0.16; 'tables,': 0.16; 'underlying': 0.16; 'wrote:': 0.18; 'later': 0.20; 'example': 0.22; 'header:User- Agent:1': 0.23; 'interpret': 0.24; 'lets': 0.24; 'login': 0.25; 'sort': 0.25; 'header:X-Complaints-To:1': 0.27; 'header:In-Reply- To:1': 0.27; 'robert': 0.30; 'along': 0.30; "i'm": 0.30; 'code': 0.31; 'relational': 0.31; 'work:': 0.31; 'class': 0.32; 'probably': 0.32; 'figure': 0.32; 'device': 0.34; 'basic': 0.35; 'classes': 0.35; 'connection': 0.35; 'but': 0.35; 'really': 0.36; 'accessing': 0.36; 'oracle': 0.36; 'subject:?': 0.36; 'url:org': 0.36; 'should': 0.36; 'throughout': 0.37; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'how': 0.40; 'even': 0.60; 'skip:n 30': 0.60; 'our': 0.64; 'different': 0.65; 'world': 0.66; 'believe': 0.68; 'eco': 0.84; 'received:125': 0.84; 'terrible': 0.84; 'url:sqlalchemy': 0.84; 'device.': 0.93; 'imagine': 0.93 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Robert Kern Subject: Re: classes and sub classes? Date: Tue, 09 Apr 2013 13:15:42 +0530 References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: 125.21.252.133 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 38 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1365493556 news.xs4all.nl 6931 [2001:888:2000:d::a6]:38205 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:43133 On 2013-04-09 11:20, Morten Guldager wrote: > 'Aloha Friends! > > I'm about to write an API against a huge propitiatory Oracle based network > inventory database. The database have many different concepts stored in it's > tables, can one concept can span over multiple tables. > > I would like to write a class for accessing each concept, but only have a single > database connection throughout the whole program. > > I imagine some code along these lines, but cant figure out how to declare the > classes that will make it work: > > # create a connection to the database and perform come basic login and > initialization > nib = NwInvDb("scott/tiger@ora") > # find a device by ip > interesting_device = nib.Device.lookup_by_ip("192.168.1.1") > > In this example I access the concept Device. > > Should I make the Device class inherit from NwInvDb? Or should I keep them > separate? Later on I think I will even have to make some sort of sub-concepts, > but lets postpone that game until I really have really seen the need! You probably want to use an off-the-shelf ORM (Object Relational Mapper) instead of writing your own ad hoc ORM. http://www.sqlalchemy.org/ -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco