I use PostgreSQL exclusively too, and rely on tons of constraints within the db - from unique indexes built through functions, to actual functions themselves.
I still, pretty much, always query the db to check for a duplicate value or possible constraint violation. 1- It's easier than parsing errors. plus you don't have to continually flush() or save() to trap the error. 2- There's really not much of a performance hit on any site i've ever worked on. In terms of the MVC debate - I've gone through the entire array of options that Mike Orr has illustrated ( though not all in Pylons ). I've had Models that have most of the logic, and the Controllers just call them... I've had Models that have no logic... and I've had Models that wrap ORMs as an abstraction layer, so I can use multiple backends (or ORMs ) easily. After years of struggle, I've ended up with this approach: - I put 'search' and 'new' functions in the model. I also put 'render' functions too ( like model.F_url() to display a url ) - If more than one controller needs to do similar operations on the model, I break it out into a helper method and stash it as a library function. The problem I encountered with putting too much logic in the models, is that MANY of my models were highly interrelated with other models. >From a maintenance and testing standpoint, this created too many headaches. I really don't like 'horizontal' interactions of models creating and modifying one another. So many issues arose. Examples that caused issues for me were Group creates / controls Members ( and vice versa ); or if Account creates AccountAsset or ApiKey. I can't recall if I had the most issues with Python or Perl or something else... but with horizontal interaction within the model, I always had issues of inclusion order / dependencies / etc. So I've found it simpler that each Model is only concerned with a representation of One member of its own class -- and that a Controller , or helper function , handles the interrelation of all of them. -- You received this message because you are subscribed to the Google Groups "pylons-discuss" group. To post to this group, send email to pylons-disc...@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
