code: def register_model_converter(model, app):
      
      if hasattr(model, 'id'):
          class Converter(_ModelConverter):
              _model = model
          app.url_map.converters[model.__name__] = Converter
docs: Add url converter for model
  
      Example:
          class Student(db.model):
              id = Column(Integer, primary_key=True)
              name =  Column(String(50))
  
          register_model_converter(Student)
  
          @route('/classmates/<Student:classmate>')
          def get_classmate_info(classmate):
              pass
  
      This only support model's have single primary key.
      You need call this function before create view function.