We have a database structure dictated by Hibernate/Java. The java
version is
used for runtime and Ruby/Rails for administration/integration etc…
We have a structure where a Channel holds a ChannelBehaviour (in java).
The
ChannelBehaviour is subclassed by several different classes. Every class
has
it’s own table and each table holds a reference back to the Channel
class
(Channel table itself doesn’t hold a reference to the behaviour although
the
objects does).
Since Ruby has duck typing I don’t have to inherit a ChannelBehaviour
for
each behaviour in Rails. I was thinking of having a module instead that
each
behaviour class needs to include. This could ensure that the behaviour
class
is added to Channel to be used when generating SQL statements to find
the
referenced behaviours from Channel (using “union” or something like
that).
Anyone has any ideas how this best would be done?
Another problem I have is that Hibernate requires all ids in the various
behaviour tables to be unique over all of the tables (ie a
MulticastChannelBehaviour and a DvbtChannelBehaviour cannot have the
same id
despite living in different tables). In java this is handled
transparently
by Hibernate where Hibernate uses a sequence table in the database to
generate ids. Because of this I have to set ids manually in the
behaviour
classes (using the same sequence table). I have tried and failed. How
should
this be done?
Answers and ideas for any of this is most welcome 
/Marcus