Hello, I had to fix a old model design flaw. The old schema implies multiple FK that are nullable depending of the context... I would use the "base parent table" antipattern that Bill Karwin is proposing to normalised db and keep referential integrity...
I would like to know what you think about this approach, if you have ever had to do it or not and if it brings really more confident into your db schema to use this antipattern or not? Finally is any of you that use this approach with web2py and how does it fits? http://stackoverflow.com/questions/2098429/how-to-handle-an-or-relationship-in-an-erd-table-design/2098477#2098477 http://stackoverflow.com/questions/3383300/foreign-key-to-one-of-many-tables More details in this PDF presentation : http://assets.en.oreilly.com/1/event/27/Practical%20Object-Oriented%20Models%20in%20SQL%20Presentation.pdf Thank Richard