state = Column(Enum(State))
value = Column(Float)
user_attributes_json = Column(String(255))
system_attributes_json = Column(String(255))
study = orm.relationship(StudyModel)
After Change
state = Column(Enum(State), default=State.RUNNING)
value = Column(Float)
user_attributes_json = Column(String(255))
datetime_start = Column(
DateTime(timezone=True), default=datetime.utcnow)
datetime_complete = Column(
DateTime(timezone=True), default=datetime.utcnow, onupdate=datetime.utcnow)
study = orm.relationship(StudyModel)