Or just leave the "polymorphic_entity='employee'" and put a CHECK constraint on the table enforcing that the value of that column is not 'employee'. Or just don't code anything that can add a generic employee :)
On Mar 10, 8:23 am, Franck <franck.pe...@gmail.com> wrote: > I'm trying to reply myself... maybe I could set *polymorphic_identity=None *at > the Employee level, and define the DB field EMPLOYEE.TYPE field as not > nullable... > > Would that work ? Is there a better way ? > > Thanks ! > Franck > > On Thu, Mar 10, 2011 at 2:00 PM, Franck <franck.pe...@gmail.com> wrote: > > Hi, > > > I read carefully the documentation at > >http://www.sqlalchemy.org/docs/orm/inheritance.htmland I'd like to > > implement a similar joined table inheritance for my application. > > > The following example is provided : > > > *mapper(Employee, employees, polymorphic_on=employees.c.type, > > polymorphic_identity='employee')* > > *mapper(Engineer, engineers, inherits=Employee, > > polymorphic_identity='engineer')* > > *mapper(Manager, managers, inherits=Employee, > > polymorphic_identity='manager')* > > * > > * > > However in my case I don't want to be able to persist some random Employee. > > All my employees should be engineers or managers. Ideally some exception > > should be thrown if I try to add an Employee object to my session. > > > Of course, I'd still like to be able to persist Engineers and Managers with > > the right type. > > > Is there a way to achieve that ? > > > Thanks a lot ! > > Franck -- 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.
