On 30.07.2006, at 15:14 Uhr, Anjo Krank wrote:
> This setup is hardly legal for single-table inheritance. Either
> your table has a non-null or it doesn't. If you want it your way,
> factor out the fields into some extra table, mark them as "allows
> null" or fix up the sql yourself.
Why shouldn't this be legal? I'm modeling entities, not tables. And
an entity might have a non null attribute even when the parent entity
doesn't know anything about this attribute.
Yes, from the database point, it's not legal - but again, I'm doing
entity modeling here, with the additional benefit of having the sql
generated for me by the application. That's all.
There are a lot of other informations in the model (the entities) not
propagated to the database like delete rules and foreign key
constrains through multiple models (the last thing is obvious because
the other model may point to a different database).
So, from my point of view, the model I create with EOModeler is NOT
the database model. It is instead the entity/object model with some
information to its mapping on the database. And from that point, I
can't be legal to have information in the model that doesn't make it
to the database. EOModeler and EOF itself seems to support the same
view, as all these things just work (inheritance, foreign key
constraints, delete rules) - without involving the database. There
are only bugs in creating the SQL for the involved database. That's all.
cug
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