From: rubyhacker@...
Date: 2005-10-27T04:52:03+09:00
Subject: Re: The "perfect" ORM?

Alexandru Popescu wrote:
> I've been working with Hibernate for quite a while and imo it is correctly
> approaching so called
> object - relational mismatch.
>
> The real good thing about this approach is that it is not obtrusive in any ways with your domain
> model objects and it let's you focus and work only on the objectual world.

That sounds good so far.

> On the dark side of the problem: you should provide in some way the mapping between the object world
> and the relational world.

Yes, that is a necessary evil. Naturally I want the toolkit to be as
smart
as possible, and its usage to be painless as possible.

> While there are a few things that could be a little simplified (like
> automatic type conversions), the big problem is the impossibility to use this simplified form on
> relationships. If the parametrized types would have been implemented without the erasure mechanism
> than this simplification could be brought further, but for the moment we have to use some other way
> to describe relations: and here comes into play the metadata.

That sounds interesting, but I did not understand any of it.  :) I am
not
sure what you mean by parametrized types, or what an erasure mechanism
is.

> There are a few different approaches
> used: metadata through external XML, metadata through javadoc comments and lately metadata through
> annotations.

All of these seem wrong to me. My approach will be: Metadata through
Ruby code
external to the stored objects.

I will try to give an example in a week or so.


Thanks,
Hal