Re: [SQLObject] thoughts on structure and components

[Bud P. B. <bu...@si...>]

On 08 May 2003 09:44:21 -0500
Nick <ni...@dd...> wrote:

> On Thu, 2003-05-08 at 04:37, Bud P.Bruegger wrote:
> > Backend:
> >   An object that manages the interaction with the actual database.
> >   It has the following components:
> >   - mapping
> >   - dbDriver
> >   - dbConnection
> 
> Don't forget cache somewhere, which probably makes more sense to put
> here than in the Connection.

Absolutely right!

> > Mapping:
> >   Description of the physical representation in a dbms-independent way.  
> 
> Isn't mapping dependent on the way the data is stored in the database? 
> Maybe I'm misunderstanding what you mean by mapping.

Yes, the mapping describes how objects are stored in the dbms but
abstracts from the details that differ with the actually used dbms
(mysql, postgres, etc).  

> > Attribute:
> >   A high-level physical type to represent the higher-level physical rep. 
> >   This includes marshalling to and from a lower-level representation. 
> >   Marshalling can do things such as encoding structured objects (phone
> >   number with country and area code) to strings, pickling, mapping a single
> >   attribute (a point) to multiple columns (x, y or lat,long), etc.  
> 
> How does this relate to mapping?  It sounds similar.

It's a component, have a look at the UML class diagram that I
attached..

Thanks for the feedback

--b