On Sat, 7 Feb 2004, Gus Heck wrote: > Interesting. is there an example of this somewhere? How would this work > with JDO? Can this table be generated as needed somehow? That would be > ideal. I would like my objects to simply use their collections as normal > java collections, otherwise, I have to go back and carefully analyze my > object model to find all the collections that each object might wind up in.
This table is generated by the xdoclet module, so in a sense it is static. You can have a look at the second example of the ojb.collection tag to see how a m:n collection is defined where the 'other' end has no knowledge that it is part of an association. > So does this mean I can only have collections of a specific element > type? What about collections that hold multiple types? Is it impossible > to store them? I think that specification of element types is supposed > to be optional for JDO. (allowing the implementation to optimize if it > is specified) In normal OJB (PB, ODMG) you specify 1:n associations (references), 1:n and m:n associations (colletions) between persistent classes (types that have a class descriptor). If you want a somewhat generic collection you have to find a common basetype of all possible element objects, which can be made persistent. Especially it needs to have primary keys. I don't know anything about JDO, but I guess it is the same there. Tom --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
