CODEWITHSUNDEEP
pythonmysqlsqlalchemy
wiko
wiko

Reputation: 453

sqlalchemy.orm.exc.FlushError: Instance has a NULL identity key

I inteded to submit data to mysql table using sqlalchemy from Python27. when I tried to run this file, it shows an error like this

sqlalchemy.orm.exc.FlushError: Instance <TravelScheduleDetailRepository at 0x7f0fc07c8950> has a NULL identity key.  If this is an auto-generated value, check that the database table allows generation of new primary key values, and that the mapped Column object is configured to expect these generated values.  Ensure also that this flush() is not occurring at an inappropriate time, such aswithin a load() event.

afther that it successfully made a new row on the mysql table although all the columns are null

here's my class

class TravelScheduleDetailRepository(Base):
    __tablename__ = 'Schedule_Detail'
    schedule_id = Column(String(7), primary_key = True)
    transport_id = Column(String(5))
    transport_type = Column(String(80))
    transport_company_name = Column(String(80))
    departure_city_id = Column(String(3))
    departure_country_id = Column(String(3))
    destination_city_id = Column(String(3))
    destination_country_id = Column(String(3))
    departure_date = Column(DateTime)
    available_seat = Column(Integer, autoincrement=False)

    def __init__(self, schedule_id, transport_id, transport_type, transport_company_name, departure_city_id, departure_country_id, destination_city_id, destination_country_id, departure_date, available_seat):
            self.schedule_id
            self.transport_id
            self.transport_type
            self.transport_company_name
            self.departure_city_id
            self.departure_country_id
            self.destination_city_id
            self.destination_country_id
            self.departure_date
            self.available_seat

    def __repr__(self):
            return "<TravelScheduleDetailRepository(schedule_id='%s', transport_id='%s', transport_type='%s', transport_company_name='%s', departure_city_id='%s', departure_country_id='%s', destination_city_id='%s', destination_country_id = '%s', departure_date = '%d', available_seat='%i')>" % ( self.schedule_id, self.transport_id, self.transport_type, self.transport_company_name, self.departure_city_id, self.departure_country_id, self.destination_city_id, self.destination_country_id, self.departure_date, self.available_seat)

and here's how I insert it to mysql

    Session = sessionmaker(bind=engine)
session = Session()
newSchedule = TravelScheduleDetailRepository(schedule_id='bbb', transport_id='33', transport_type='Hell', transport_company_name='Slick', departure_city_id='GGG', departure_country_id='FOO', destination_city_id='WWW', destination_country_id='FFF', departure_date='03-03-2011', available_seat=40)
session.add(newSchedule)
session.flush()
session.commit()

Thank you

Upvotes: 4

Views: 11718

Answers (1)

van
van

Reputation: 76952

Your __init__ method is incomplete: in order to assign parameters into member variables you should actually assign them:

def __init__(...):
    self.schedule_id = schedule_id
    ...

You can call before you call flush, just call print(newSchedule) and you will see that all your fields are empty.

Upvotes: 6

Related Questions