Path: newssvr20.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!prodigy.com!in.100proofnews.com!in.100proofnews.com!fu-berlin.de!uni-berlin.de!66.250.41.69!not-for-mail From: "Alan" Newsgroups: comp.databases.theory Subject: Re: Designing Default Value Date: Mon, 20 Oct 2003 16:08:13 -0400 Lines: 36 Message-ID: References: NNTP-Posting-Host: 66.250.41.69 X-Trace: news.uni-berlin.de 1066680480 29961555 66.250.41.69 (16 [114862]) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Xref: newssvr20.news.prodigy.com comp.databases.theory:21804 Values do not belong in an ERD. They belong in the data dictionary document that is submitted with the rest of your assignment. What you are talking about *is* an implementation detail, not a design detail. Depending on the tool you are using, you may be able to build the list and select the default automatically, but they still don't belong on the ERD. An ERD shows abstract business relationships among the data- not implementaion level items. "Michael Fuchs" wrote in message news:bn17k5$mjl$1@bird.wu-wien.ac.at... > Having a list of values in one table, what would be the clean way to go > to *design* a default value? (in an ER diagram) > > I do NOT want to know about setting default values for CREATE TABLE > statements when adding data, the question is how to design this > information so that it can be read into my application. > > example table: > > ---------- > |Currency| now i would like to have USD > |--------| as the default value, > | EUR | the application should then be > | USD | able to preselect this value > | CHF | to make usage easier; > | CAD | > ---------- > > Thank you very much everybody, your help is enormously appreciated! > > Michael >