Re: complex referential integrity constraints

to attack eachother.
>
> Depending on what you're modelling, even this could be too simple -- for
> example, while a single wolf is unlikely to attack a lion, a pack of
> wolves have a lot more probability of doing so.
>
> Do you keep packs of wolves in your barn?  If so, watch your lions.

Well from the previous thread that discussed the use of the <animal> table and sub-set tables
<prey> and <preditor>, if a preditor can attach a prey item or preditor item, then a table
relation only needs to be created between <preditor> and <animal>.  This way only preditors can
attack, but they can attach any other animal preditor or prey.

Regards,
Richard Broersma Jr.