Re: Application Design: Where to implement historical revisions of objects

But in the one-table holds all system, the Model Object need to know about it. 
  i.e. "Select top 1 from data where serialnumber = 3821 order by revision desc"
And off hand, it would make retrieving a whole data set of say- all the current data involve a subquery to find the most recent data revision for each serialnumber.

I don't at all mean to discount the system, but I have yet to find a good pattern for dealing with multiple variants of the same datarow/set.

Colin

On 5/25/07, Michelle Konzack <linux4michelle@xxxxxxxxxx> wrote:

Hello Colin,

Am 2007-05-23 13:10:42, schrieb Colin Ross:
> In Practice:
> An application has a model class of "PageContent" which represents the
> content that is shown on a certain page. Users of the system are
> authenticated, then able to edit the content. From an application design
> point
> of view, where should the logic and underlying system be for the management
> of historical revisions.

I have something similar, exactly, a Database of military data and data
sets are never modified but added.

So, I give each dataset a serialnumber and a revision 0. Then if the
dataset was modified I change the revision to a higher number and add
the whole dataset into a new row.

This thing is done using trigers.

Greetings
    Michelle Konzack
    Systemadministrator
    Tamay Dogan Network
    Debian GNU/Linux Consultant


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