How do you validate?

broken.py

from eve import Eve
from eve_sqlalchemy import SQL
from sqlalchemy.ext.declarative import declarative_base
from eve_sqlalchemy.decorators import registerSchema
from eve_sqlalchemy.validation import ValidatorSQL
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.ext.hybrid import hybrid_property
from sqlalchemy.orm import column_property, relationship
from sqlalchemy import func
from sqlalchemy import (
    Column,
    String,
    Integer,
    ForeignKey,
    DateTime)

Base = declarative_base()


class People(Base):
    __tablename__ = 'people'
    id = Column(Integer, primary_key=True, autoincrement=True)
    firstname = Column(String(80))
    lastname = Column(String(120))
    fullname = column_property(firstname + " " + lastname)


class Invoices(Base):
    __tablename__ = 'invoices'
    id = Column(Integer, primary_key=True, autoincrement=True)
    number = Column(Integer)
    people_id = Column(Integer, ForeignKey('people.id'))
    people = relationship(People, uselist=False)


registerSchema('people')(People)
registerSchema('invoices')(Invoices)

settings = {'SQLALCHEMY_DATABASE_URI':  'sqlite:///data.sq3',
            'DOMAIN': {'people': People._eve_schema['people'],
                       'invoices': Invoices._eve_schema['invoices'],
                       },
            }
settings['DOMAIN']['people'].update({'resource_methods': ['GET', 'POST', 'DELETE']})


app = Eve(data=SQL, settings=settings, auth=None, validator=ValidatorSQL)
db = app.data.driver
Base.metadata.bind = db.engine
db.Model = Base
db.create_all()

app.logger.debug(People._eve_schema['people'])

db.session.add(People(firstname='Dude', lastname='Man'))
db.session.commit()

if __name__ == '__main__':
    app.logger.info('Starting with server as __main__')
    app.run(host='0.0.0.0', port=80, debug=True)