Path: newssvr20.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!pd7cy2so!pd7cy1no!shaw.ca!border1.nntp.ash.giganews.com!border2.nntp.sjc.giganews.com!border1.nntp.sjc.giganews.com!nntp.giganews.com!local1.nntp.sjc.giganews.com!nntp.golden.net!news.golden.net.POSTED!not-for-mail NNTP-Posting-Date: Mon, 02 Feb 2004 16:30:36 -0600 From: "Bob Badour" Newsgroups: comp.databases.theory References: <2GMQb.26802$zj7.13126@newsread1.news.pas.earthlink.net> <401ed196_1@news.vic.com> Subject: Re: Entity data spread over multiple tables Date: Mon, 2 Feb 2004 17:29:54 -0500 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: Lines: 82 NNTP-Posting-Host: 207.35.144.44 X-Trace: sv3-y9wX+MjFp5t03dFdgSt9fjVo2/bI5FlpBXELLBJ1XatpgjOHeUDMmCHodGZRfzyus8SxYEGTLjMwjKq!ejSo/UUeYBfzcREtIGXORUFKyzlW2umh7cqO53ac5qXV7QqzLOlO62iURapB6T3x7QKu5WDR X-Complaints-To: abuse@golden.net X-DMCA-Complaints-To: abuse@golden.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.1 Xref: newssvr20.news.prodigy.com comp.databases.theory:23725 Hi Parker, I can't point at me to show you my name or my ID either. Heck, I don't even have rings for you to cut me in half and count to calculate my age. Regards "Parker Shannon" wrote in message news:401ed196_1@news.vic.com... > Hello John, > > The "Participants" table is called Person. A Person has many Locations. A > Person has many Locations and one Location may have many Persons. > > The relation that resolves this many-to-many is called the PersonLocation. > Person, Location and PersonLocation are all classes. > > tblPerson > Id AutoIncrement, Unique > Name Text > FirstName Text > MiddleInitial Text > LastName Text > etc. ........ > > tblLocation > Id AutoIncrement, Unique > StreetAddress Text > City Text > State Text > ZipCode Text > etc. ....... > > PersonLocation > PersonId > LocationId > Floor Text > SuiteNumber Text > PhoneNumber Text > FAXNumber Text > etc. ........ > > Note: All "pieces of a Participants identity" belong in the Person table. > Not all over the place. These are called attributes, which are physical > characteristics of a Person. This is one reason address attributes belong > in Location. Address attributes are not physical characteristics of a > Person. You can't point to yourself and show me "your city". > > Regards . . . > > "John O'Conner" wrote in message > news:2GMQb.26802$zj7.13126@newsread1.news.pas.earthlink.net... > > Hi all, > > > > In my Little League db, PARTICIPANTS have 0, 1, 2, or 3 different PHONE > > numbers. I've modeled this by creating a separate PHONE table containing > > a number, phone type, and participant id. > > > > Is this the typical design for attaching 0 or more of the same attribute > > to an entity? I see the benefit being that no PHONE columns are used > > when a PARTICIPANT doesn't have one...with the downside that PHONE is a > > separate table, and I have to access a second table to collect all info > > for a single PARTICIPANT. Actually, I have several different tables with > > pieces of a PARTICIPANTS identity. Placing data about a single entity in > > other tables must be a known, common situation with anthing but trivial > > databases, right? > > > > This rubs me a little funny because I would model this differently in a > > programming language like Java. I would probably make PHONE an array > > within PARTICIPANT classes. The array could contain 0 or more actual > > PHONE instances. The PHONE info is right there with the PARTICIPANT > > object in the programming language...however, my db model is quite > > different. Bothersome....do other people hit this type of modeling > > problem often? Is this a common db design pattern? > > > > Regards, > > John O'Conner > >