On Jan 18, 2011, at 9:42 AM, Erkan Özgür Yılmaz wrote: > Hi everybody, > > (fast start :) ) > I have a class hierarchy and I'm using joined table inheritance, but my > classes are not always going to be used with SQLAlchemy (or I plan to give > the freedom to people to use these classes anywhere they want). > > Anyway I was using the "entity_type" column in my base table to map the > polymorphic_identity. It was nice to have the "entity_type" variable *after* > mapping with SQLAlchemy. Now, I decided to add this variable to all my > classes as a new class variable. So my problem is when I map with SQLAlchemy > the variable becomes an sqlalchemy.orm.attributes.InstrumentedAttribute and > prints out None before committing the objects, so I created another column > for the discriminator with the name "db_entity_type" now I'm not able to use > the default value for "entity_type" from the class. Is there a solution for > that?
0.7 has the polymorphic discriminator column auto-populated when you first create an object, so you wouldn't have this issue then. For now keep your db_entity_type as the mapped column, keep entity_type as class based, and use it in the mapping: class MyClass(MyParent): entity_type = 'myclass' mapper(MyClass, mytable, inherits=MyParent, polymorphic_identity=MyClass.entity_type) > > Thanks... > > E.Ozgur Yilmaz > Lead Technical Director > eoyilmaz.blogspot.com > www.ozgurfx.com > > -- > 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.
