Hi, Yes, I agree your statement. I like OJB, but sometimes I feel OJB does not continue enhanceing its mapping capability. Hibernate does have better mapping capability. Since the introduction of "anonymous field" into OJB which I quite like it, OJB does not improve mapping capability much. Maybe too much effort is taken on JDO implementation. But since JDO 1.0 itself does not regulate much about OR mapping (it is heard that in 2.0, much regulatin will be made), good OR mapping mechanism should be borrowed from some other good ideas like Hibernate.
By the way, I like the embedded (nested) field function in OJB. Hibernate has similar function called component, but for deeper nesting its configuration is not that easy. Archie --- Rice Yeh <[EMAIL PROTECTED]> wrote: > > > > Hi, > > I have been using OJB for some period. I am > taking > > a > > project left by a partner that uses Hinbernate for > > persistence. So I start studying Hibernate. > > Hibernate > > has a mapping function called "any type mapping" > > that > > is defined as the follows: > > > > "The <any> mapping element defines a polymorphic > > association to classes from multiple tables. This > > type > > of mapping always requires more than one column. > The > > first column holds the type of the associated > > entity. > > The remaining columns hold the identifier. It is > > impossible to specify a foreign key constraint for > > this kind of association, so this is most > certainly > > not meant as the usual way of mapping > (polymorphic) > > associations." > > > > This kind of mapping is quite useful when dealing > > with > > fields of java.lang.Object or interface. However, > as > > I > > know, there is no such support in OJB. I try to > > study > > the source code of OJB, but am still not able to > > figure out the way to modify it (The xml mapping > > handling code is a little hard to understand, just > > wonder if it is possible to re-write it with Jibx > to > > make it more concise). > > > > Regards, > > Rice > > > > > > __________________________________ > > Do you Yahoo!? > > Exclusive Video Premiere - Britney Spears > > http://launch.yahoo.com/promos/britneyspears/ > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: > > [EMAIL PROTECTED] > > For additional commands, e-mail: > > [EMAIL PROTECTED] > > > > > __________________________________ > Do you Yahoo!? > Exclusive Video Premiere - Britney Spears > http://launch.yahoo.com/promos/britneyspears/ __________________________________ Do you Yahoo!? Exclusive Video Premiere - Britney Spears http://launch.yahoo.com/promos/britneyspears/ --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
