Re: [gnome-db] Entity-Relation to Relational mapping

[Vivien Malerba <vmalerba gmail com>]

On Fri, 5 Nov 2004 10:14:30 -0700, Neil Zanella <nzanella gmail com> wrote:
> Hello,
> 
> Does mergeant deal with Entity-Relation to Relational mapping. Right
> now the only Open

Right now Mergeant translates the foreign key constraints into a
graphical representation to make it easy to see the relations between
the tables in the database (have a look at
http://malerbavintner.free.fr/mergeant_screenshots/SC1.png) to see
what it looks like.

> Source I know of that can do anything with ER models is Dia and it
> doesn't do much other
> than letting you place a few widgets down and even that is missing
> some features and a
> little buggy. I wonder whether Mergeant plans do incorporate:
> 
> 1. An ER modeler
> 2. Functions to map ER models to Relational ones

Yes, both of these. Many pieces of the puzzle are already in place
(canvas items for the graphical representations, which can be extended
for example).

Here is what needs to be done:
-> create classes for ER objects (entities, relations, notes, etc)
-> create missing classes for graphical representation
-> create a ER to relational translation (which is quite easy)

Optionnaly, but would be good to have:
-> create a relation to ER (which is more complex)
-> think about a good way to keep updated the ER model and the real
database structure as represented in the data dictionnary (this needs
a bit more thoughts).

> 
> ER models can be huge, and the user inteface is crucial here.
> Unfortunately I am not able to compile mergeant and the screenshots
> in the user manual are broken so I cannot get a feel for what it looks like.

There are som screenshots at http://malerbavintner.free.fr/mergeant_screenshots/

I can send you a compiled version if you want. Tell me.

> 
> Does it have a GUI of some sort with a canvas where the user can draw
> just like in Dia?

Yes.

Cheers,

Vivien