old_contents: import datetime, re;
  from sqlalchemy.orm import validates;
  from server import DB, FlaskServer;
  
  
  class Orders(DB.Model):
  	id = DB.Column(DB.Integer, primary_key=True, autoincrement=True);
  	order_no = DB.Column(DB.Integer(20));
  	serial_id = DB.relationship(DB.Integer. DB.ForeignKey('serial.id'), lazy='joined');
  	approx_cfs = DB.Column(DB.Float);
  	approx_hrs = DB.Column(DB.Float);
  	approx_af = DB.Column(DB.Float);
  	district_id = DB.relationship(DB.Integer, DB.ForeignKey('district.id'));
  	order_time = DB.Column(DB.DateTime);
  	balance = DB.Column(DB.Float);
  	adjust = DB.Column(DB.String(20), nullable=True);
  	pending_analysis = DB.Column(DB.Boolean);
  	created_by = DB.relationship(DB.Integer, DB.ForeignKey('users.id'));
  	created_at = DB.Column(DB.DateTime);
  	updated_by = DB.relationship(DB.Integer, DB.ForeignKey('users.id'), nullable=True);
  	updated_at = DB.Column(DB.DateTime, nullable=True);
  
  	def __init__(self, order_no, approx_cfs, approx_hrs, approx_af, order_time, balance, adjust, pending_analysis, created_at,updated_at):
  		self.order_no = order_no;
  		self.approx_cfs = approx_cfs;
  		self.approx_hrs = approx_hrs;
  		self.approx_af = approx_af;
  		self.order_time = order_time;
  		self.balance = balance;
  		self.adjust = adjust;
  		self.created_at = datetime.datetime.now();
  		self.updated_at = self.created_at;
  
  
new_contents: import datetime, re;
  from sqlalchemy.orm import validates;
  from server import DB, FlaskServer;
  
  
  class Orders(DB.Model):
  	id = DB.Column(DB.Integer, primary_key=True, autoincrement=True);
  	order_no = DB.Column(DB.Integer);
  	serial_id = DB.relationship(DB.Integer. DB.ForeignKey('serial.id'), lazy='joined');
  	approx_cfs = DB.Column(DB.Float);
  	approx_hrs = DB.Column(DB.Float);
  	approx_af = DB.Column(DB.Float);
  	district_id = DB.relationship(DB.Integer, DB.ForeignKey('district.id'));
  	order_time = DB.Column(DB.DateTime);
  	balance = DB.Column(DB.Float);
  	adjust = DB.Column(DB.String(20), nullable=True);
  	pending_analysis = DB.Column(DB.Boolean);
  	created_by = DB.relationship(DB.Integer, DB.ForeignKey('users.id'));
  	created_at = DB.Column(DB.DateTime);
  	updated_by = DB.relationship(DB.Integer, DB.ForeignKey('users.id'), nullable=True);
  	updated_at = DB.Column(DB.DateTime, nullable=True);
  
  	def __init__(self, order_no, approx_cfs, approx_hrs, approx_af, order_time, balance, adjust, pending_analysis, created_at,updated_at):
  		self.order_no = order_no;
  		self.approx_cfs = approx_cfs;
  		self.approx_hrs = approx_hrs;
  		self.approx_af = approx_af;
  		self.order_time = order_time;
  		self.balance = balance;
  		self.adjust = adjust;
  		self.created_at = datetime.datetime.now();
  		self.updated_at = self.created_at;
  
  
subject: Update orders.py