Re: History tracking in databases

I don't think the "old box" is a box at all, it's historical information about a box. So, I'd have three entities: Crate, Box, Box_history. A Box would reference a Crate, A Box_history would of course reference its box. Don't mix 'history' with 'active' data, it complicates matters enormously. -- Kind reGards, Gerard (ghp@santens.be; ghp@skynet.be) bhq001@email.mot.com schreef in artikel <872763022.5320@dejanews.com>... > Hi, > > I am trying to develop a relational database for a > project at work. > Currently we are at the logical design phase for > this database. > The database structure is very hierarchical due to > the data requirements > of the project. > As part of the design requirements, the database > must provide means of > tracking historical data. This is further explained > below: > > Say you have a CRATE (CRATE1) which can contain > smaller BOXes (BOX1,BOX2 > etc.) > > CRATE1 is related to BOX1 and BOX2. > > Each BOX contains information specific to itself. > > Say BOX1 information was changed for some reason but > we would still like > to know the previous information for BOX1. > > CRATE1 is now related to BOX1,BOX1(old),BOX2 > > Question: How would this kind of relationship be > implemented in an RDBMS? > > Thanks in advance for any advice given. > > H.Quan > > -------------------==== Posted via Deja News ====----------------------- > http://www.dejanews.com/ Search, Read, Post to Usenet >