Model is not defined

Question

I'm using Flask and Peewee to create models for Users and Appointments, and each of them have a ForeignKeyField referencing each other. The problem is, if I define one above the other, Flask will give me x is not defined.

For example:

class User(Model):
   appointments = ForeignKeyField(Appointment, related_name='appointments')

class Appointment(Model):
   with_doctor = ForeignKeyField(User, related_name='doctor')

This would return 'User' is not defined. How am I able to fix this problem?

Answer 1

You generally don't define the foreign key on both sides of the relationship, especially when the relationship isn't a one-to-one.

You should also set the related_name to something that makes sense on the related model. user.appointments is probably a better name for accessing a User's Appointments than user.doctor.

class User(Model):
   pass

class Appointment(Model):
   with_doctor = ForeignKeyField(User, related_name='appointments')