Intro/Question

Hi folks,

First off, let me say that I'm pretty impressed with what you have 
started here.  I've been in a similar situation a few times, and decided 
something like this was sorely needed, but never had the time to put 
anything quite so coherent together to address it.  So, nice work.

I'm trying to get started small, and have hit a question.

I'm trying to think of this in terms of having the 'pymodel' file be the 
central repository for schema related issues.  That seems to be the 
design intent anyway -- and really how I would like to do things 
(central location).

Suppose I'm going to implement /etc/passwd /etc/group type concepts.  
This gives 'user' 'group' and 'usergroup' entities, plus associations.  
Great.

using groupID and userID as the primary keys, and the correlation table 
is the tuple of the two.

Heres' my issue.  Clearly you want to enforce uniqueness of username 
(strings) as well as user-ids and integer primary keys.  Further, this 
is something you need the DBMS to enforce.  Since I'm effectively 
specifying my schema in pymodel, it would seem reasonable to be able to 
add this type of constraint to that specification.

Either that, or have a coherent way of maintaining them separatly in a 
non-disjoint sort of way.

Looking for either something I've missing in the modelling, or a good 
technique to handle this class of problem.

Thanks,
Clay Hopperdietzel


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