Python + Flask + Persistance VIII

Relationship


Update the Model


backref='engineer'   the name of the object to do the relationship

lazy -  how to load relationships

lazy = 'select'  (default)
lazy = 'join'
lazy = 'subquery'
lazy = 'dynamic'




from datetime import datetime

from sqlalchemy import desc
from ict import db

class Ticket(db.Model):
id = db.Column(db.Integer, primary_key=True)
signum = db.Column(db.String(10), nullable=True)
comments = db.Column(db.String(255), nullable=True)
engineer_id = db.Column(db.Integer, db.ForeignKey('engineer.id'), nullable=False)

@staticmethod
def newest(num):
return Ticket.query.order_by(desc(Ticket.signum)).limit(num)

def __repr__(self):
return "<Ticket '{}' : '{}'> ".format(self.signum, self.comments)

class Engineer(db.Model):
id = db.Column(db.Integer, primary_key=True)
signum = db.Column(db.String(10), unique=True)
name = db.Column(db.String(100), nullable=True)
tickets = db.relationship('Ticket', backref='engineer', lazy='dynamic')


def __repr__(self):
return "<Engineer '{}' : '{}' >".format(self.signum, self.name)