Re: Natural keys vs Aritficial Keys

From: paul c <>
Date: Fri, 22 May 2009 21:00:36 GMT
Message-ID: <UnERl.27765$Db2.17452_at_edtnps83>

Bob Badour wrote:
> Dave Hughes wrote:
>>> But how many "Great Blunders" does the SQLAlchemy ORM make?
>> I suspect I'd have to do a bit of revision to properly answer this,
>> but the following quote from the blurb on SQLAlchemy's homepage
>> suggests to me that it at least provides the means to avoid the first
>> Blunder:
>> "Map objects to not just tables but to any arbitrary join or select
>> statement"
>> Which is not to say that people won't Blunder when using it, but at
>> least it doesn't force one to Blunder (which I suspect is all one can
>> reasonably ask of an ORM).

> Nope, that's still the first blunder: mapping object instances to 
> tuples. Derived tuples are still tuples.

Maybe he has in mind mapping objects to tables that don't describe relations, which I gather are possible in SQL, similarly while relational joins or selects can always be seen as relations, there are some SQL statements that don't, such as outer join.

If that's right, then the homepage author should do the honest thing and say "Map objects to non-relational tables and non-relational join or select statements"! Received on Fri May 22 2009 - 23:00:36 CEST

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