I'm attempting to develop a function within the PlayerAt table to retrieve records from a PlayerOc table based on a filter that utilizes the timedelta feature. Below is an abbreviated version of the class:
class PlayerAt(Base):
id_ = sa.Column(sa.Integer, primary_key=True)
birth_date = sa.Column(sa.Date, index=True)
def return_player_oc_records(self):
session = sa.orm.object_session(self)
qry = session.query(PlayerOc)
qry = qry.outerjoin(PlayerAt)
qry = qry.filter(PlayerOc.birth_date >= self.birth_date - dt.timedelta(weeks=4))
recs = qry.all()
return recs
However, upon executing the function, I encounter the following error:
TypeError: unsupported operand type(s) for -: 'NoneType' and 'datetime.timedelta'
This arises because certain records in the PlayerAt table lack a birth_date entry.
I've attempted converting the filter to:
qry = qry.filter(PlayerOc.birth_date >= sa.func.IF(self.birth_date != None, self.birth_date - dt.timedelta(weeks=4), None))
Nevertheless, I receive the same error message.
Any suggestions for resolving this issue?