From oracle-l-bounce@freelists.org Mon Aug 8 10:31:29 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j78FVTpM016527 for ; Mon, 8 Aug 2005 10:31:29 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air891.startdedicated.com (8.12.10/8.12.10) with ESMTP id j78FVPIP016511 for ; Mon, 8 Aug 2005 10:31:25 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id ED1A11DD41C; Mon, 8 Aug 2005 10:31:22 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 02796-08; Mon, 8 Aug 2005 10:31:22 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 52BE11DD4ED; Mon, 8 Aug 2005 10:31:22 -0500 (EST) X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by Ecartis Subject: RE: Counterquestion - is Oracle a He or a She - or an It or a hermaphrodite Date: Mon, 8 Aug 2005 08:29:28 -0700 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Counterquestion - is Oracle a He or a She - or an It or a hermaphrodite Thread-Index: AcWcLVSor0Gshn2jQMmMYD/36zIC3wAABTVA From: "Kennedy, Jim" To: "Leandro Guimaraes Faria C. Dutra" Cc: "Niall Litchfield" , , , X-OriginalArrivalTime: 08 Aug 2005 15:29:29.0084 (UTC) FILETIME=[F790A3C0:01C59C2D] X-archive-position: 23559 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: jim_kennedy@mentor.com Precedence: normal Reply-To: jim_kennedy@mentor.com X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at avenirtech.net X-mailscan-MailScanner-Information: Please contact the ISP for more information X-mailscan-MailScanner: Found to be clean X-MailScanner-From: oracle-l-bounce@freelists.org X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on air891.startdedicated.com X-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,SUBJ_HAS_SPACES autolearn=no version=2.63 -----Original Message----- From: Leandro Guimaraes Faria C. Dutra [mailto:ldutra@toyota.com.br] Sent: Monday, August 08, 2005 8:21 AM To: Kennedy, Jim Cc: Niall Litchfield; oracle-l@freelists.org; oracle-l-bounce@freelists.org; psinger1@chartermi.net Subject: RE: Counterquestion - is Oracle a He or a She - or an It or a hermaphrodite oracle-l-bounce@freelists.org gravou em 2005-08-08 12:20:02: > So your DB is context-dependent. NULLs attack. NULLs are ambiguous, their interpretation depend on context. If SQL allowed us to define special values, we'd have a better solution, as currently exist in Tutorial D (only implemented in a toy DBMS, Rel) and D4 (Alphora Dataphor). -- Leandro Guimarães Faria Corcete DUTRA Administrador de Bases de Dados +55 (11) 4390 5383 Toyota do Brasil Ltda ldutra@toyota.com.br São Bernardo do Campo, SP BRASIL This message (including any attachments) is confidential and may be privileged and intended solely for the use of the person/entity to whom it is addressed. If you have received it by mistake please notify the sender by returning via e-mail as well as delete this message from your system. Any unauthorized use or dissemination of this message in whole or in part is prohibited. Please note that e-mails are susceptible to change. TOYOTA DO BRASIL LTDA (including its group companies) shall not be liable for the improper or incomplete transmission of the information contained in this communication, neither for personal, nonbusiness related information nor opinion sent through this email or even for any delay in its receipt or damage to your system. TOYOTA DO BRASIL LTDA (or its group companies) does not guarantee that the integrity of this communication has been kept nor that this communication is free of viruses, interceptions or interference. No, NULLS mean no data. My example made a lot of sense, we don't have any data on whether the patient has any allergies or not. Why don't we have any data? We never asked the question. We can not medically assume he does or does not have allergies. Sure there is "context" in the sence that the column is designated as the FK into the allergy table and not the FK into the medication table. For medications a similar statement could be made. NULL for the foreign key into the meds table means We don't know if he is taking medication or not. Jim -- http://www.freelists.org/webpage/oracle-l