On May 22, 2007, at 5:59 AM, Ricardo Andere de Mello wrote:

anyway, the "selected automatically" part is not simple. ;-)
every relatioship must be historical and means you will need a join table to
do it.

I haven't studied this in detail, but it seems that if you have a foreign key in one table that refers directly to another table, and if you select the historically correct rows from each table, then a join table isn't needed. This works even in the case of changing the foreign key value, since the historically correct version of the row has the correct foreign key value.

What case requires a separate join table?



Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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