Re: JDO comparisons

Robert Klemme <robert.klemme_at_myview.de> wrote in message news:<3C70D7B3.686DF5AF_at_myview.de>...
> Eric Samson schrieb:
> >
>
> > Robert Klemme <robert.klemme_at_myview.de> wrote in message news:<3C6D461D
> .E648987A_at_myview.de>...
> > > Eric Samson schrieb:
> > > > Also JDO defines a Query Language embedded with Java.
> > >
> > > ... which is VERY limited at the moment. for example: you cannot
> > > query maps, only simple collections.
> > How do you simply QUERY MAPS with JDBC ?
> > How do you deal with simple collections or inheritance ?
>
> collections and maps is exactly the stuff where RDBMS shine.
>
> that's what they are build and optimized for. a table with two
> or more columns representing an association (or a map if you
> like) can be easily queried by a select statement. and you can
> narrow output down to exactly that portion of the map you want.
>
> robert
>
> --
>
> Robert Klemme
> Software Engineer
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> myview technologies GmbH & Co. KG
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> -------------------------------------------------------------

Robert

we all know the very simplistic RDBMS storage mechanism is very flexible in terms of queries and so on.

But the result set of a query on a table with 2 columns or more is definitely not what an object programmer would call a Collection !

RDBMS are very expressive, but very badly integrated in object languages.
This is what JDO solves (fully transparent integration within Java).

Best Regards, Received on Tue Feb 19 2002 - 10:03:15 CET