your question has arrived at the same time almost the exact same question is coming from another user Russ, so I've added an example of how to use attribute events in conjunction with a TypeDecorator, so that the data is coerced both at the database level, as well as at the attribute setter level - this is at http://www.sqlalchemy.org/trac/wiki/UsageRecipes/ValidateAllOccurrencesOfType.
On Jun 29, 2011, at 9:40 PM, Jason Denning wrote: > Hi All, > I am building a Pyramid app using SQLAlchemy for the model, and I > would like to be able to use the attributes as full-fledged objects > (i.e., I would like to be able to define methods attached to the > attributes), ideal example usage (although this is a somewhat > contrived example): > > class Phone(Base): > id = Column(Integer, primary_key=True) > phone = Column(MyPhoneType) > >>>> p1 = Phone(phone="9995551212") >>>> session.add(p1) >>>> p1.phone > '9995551212' >>>> p1.phone.prettyPrint() > "(999) 555-1212" >>>> p1.phone.foo() > "Now doing foo..." > > I have made some attempts towards this end using TypeDecorator and by > trying to extend UserDefinedType, but it seems that the instantiated > objects always have their mapped attributes converted into regular > python types (string, unicode, etc..) losing whatever methods/class > level stuff I try to define. > > I am not trying to affect any aspect of the descriptor protocol, > object management, database interaction or any other ORM type stuff - > I just want some helper methods, and maybe some instance-level > attributes to be available for certain types of mapped attributes. > > Is this possible? Should I be doing this using TypeDecorator / > UserDefinedType / other ? Is anyone else attempting this type of > thing, or am I totally crazy? > > Thanks, > Jason > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To post to this group, send email to sqlalchemy@googlegroups.com. > To unsubscribe from this group, send email to > sqlalchemy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sqlalchemy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
