relation type

[William Denton]

On 2 November 2006, Knut Hegna wrote:

> I have read the mysql-init.sql file and I wonder if you have
> considered establishing a table of relation types (with
> relation-id in one column) and then to introduce the
> relation-id in the other relation tables
>
>    work-work-relation_id,
>    work-person-relation_id,
>    work-expression-relation_id,
>    manifestation-person-relation_id,
>    ... and so on
>
> We need to know what kind of relation we're talking about
> and as I see it this can be implemented either as different
> relation tables, one for each relation type, or by
> introducing relation type in the existing tables.

We definitely need to know what kind of relation it is, but I wasn't sure, 
when I was sketching this out, how best to handle that, whether to add 
another table or use the join table.  Other tables, as you list, would 
work best, I think.  There'd be a lot of standard relations (X is editor 
of Y, C is successor to B) that could be referenced, and people should 
also be able to define their own if need be (F is an anti-matter copy of 
G).

I wasn't sure how best to get all relations working in Rails, either.  I 
read some blog entries saying many-to-many relationships had gotten easier 
to handle in edge Rails, but I didn't want to get into that just yet.  Do 
you know the best way to do this in Rails?

In my head, I image a nice Ajaxy UI where a user can see that X <---> Y 
and can edit the relation line in place, pop up a list of options to 
choose from, or add a new one.  That gets stored in the database.

Cheers,

Bill
-- 
William Denton : Toronto, Canada : www.miskatonic.org : www.frbr.org