I am creating a Point of Sales application, with the typical data hierarchy : Company->branches->Sales->SaleData, this is the model definition (Note that, the User model already prepare and working as a flask-login compatible model) :
from flask_sqlalchemy import SQLAlchemy
from main import db
from collections import OrderedDict
class Users(db.Model,object):
'''
Adding object to trun sqlalchemy into json object
'''
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(60), unique=True)
firstname = db.Column(db.String(20))
lastname = db.Column(db.String(20))
password = db.Column(db.String)
email = db.Column(db.String(100), unique=True)
role = db.Column(db.String(20))
active = db.Column(db.Boolean)
company_id = db.Column(db.Integer, db.ForeignKey('companies.id'))
def __init__(self, username=None, password=None, email=None, firstname=None, lastname=None):
self.username = username
self.email = email
self.firstname = firstname
self.lastname = lastname
self.password = password
self.active = True
self.role = 'Admin'
def is_authenticated(self):
return True
def is_active(self):
return self.active
def is_anonymous(self):
return False
def get_id(self):
return unicode(self.id)
def _asdict(self):
'''
Thanks to http://stackoverflow.com/questions/7102754/jsonify-a-sqlalchemy-result-set-in-flask
'''
result = OrderedDict()
for key in self.__mapper__.c.keys():
result[key] = getattr(self, key)
return result
class Companies(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(100), unique=True)
address = db.Column(db.String)
users = db.relation('Users', backref=db.backref('users'))
token = db.Column(db.String) #for identification of client
branches = db.relationship("Branches")
def __init__(self, name=None, address=None, token=None):
self.name = name
self.address = address
self.token = token
class Branches(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(255), unique=True)
address = db.Column(db.String)
user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
token = db.Column(db.String) #for identification of client
company_id = db.Column(db.Integer, db.ForeignKey('companies.id'))
sales = db.relation('Sales',
backref=db.backref('sales', lazy='dynamic'),
cascade="all, delete-orphan",
lazy='dynamic',
passive_deletes=True)
def __init__(self, name=None, address=None, token=None, user_id=None):
self.name = name
self.address = address
self.token = token
self.user_id = user_id
class Sales(db.Model):
id = db.Column(db.Integer, primary_key=True)
day = db.Column(db.Date)
branch_id = db.Column(db.Integer, db.ForeignKey('branches.id'))
data = db.relationship("SaleData")
def __init__(self, day=None):
self.day = day
class SaleData(db.Model):
id = db.Column(db.Integer, primary_key=True)
sale_id = db.Column(db.Integer, db.ForeignKey('sales.id'))
cash_start_of_day = db.Column(db.Integer)
cash_end_of_day = db.Column(db.Integer)
income = db.Column(db.Integer) # which is end - start
def __init__(self, cash_start_of_day = None, cash_end_of_day = None, income = None):
self.cash_start_of_day = cash_start_of_day
self.cash_end_of_day = cash_end_of_day
self.income = income
Now, if I try to add a Sales data to the branches, it didn't happen if I do this :
branch1 = company1.branches.filter().all()
I can olny do this :
branch1 = company1.branches[0]
If not using that [] operator, I got error message : AttributeError: 'InstrumentedList' object has no attribute'. I have already browse another answer here in SO, it got to do with that lazy things in backref definition, so I already modify my current model
But it seems like I am missing something here.. any clue? Thanks!
EDIT 1 : Unit test added & User Model added too
I already got a concise answer from Mark Hildreth, and it saves me a lot! Because of that, I am going to put here the complete unit test of this model. I am sure it will help newbies out there in their very first step in SQLAlchemy. So, here goes :
import unittest
from main import db
import models
import md5
import helper
class DbTest(unittest.TestCase):
def setUp(self):
db.drop_all()
db.create_all()
def test_user_and_company(self):
"""admin of a company"""
user1 = models.Users('eko', helper.hash_pass('rahasia'), 'swdev.bali@gmail.com')
db.session.add(user1)
db.session.commit()
"""the company"""
company1 = models.Companies('CDI','Glagah Kidul', 'empty')
db.session.add(company1)
company1.users.append(user1)
db.session.commit()
assert company1.users[0].id == user1.id
"""branches"""
company1.branches.append(models.Branches(name='Kopjar',address='Penjara Malaysia', token='empty token', user_id=user1.id))
company1.branches.append(models.Branches(name='Selangor',address='Koperasi Selangor', token='empty token', user_id=user1.id))
db.session.commit()
'''sales'''
branch1 = company1.branches.filter(models.Branches.name=='Kopjar').first()
assert branch1.name=='Kopjar' and branch1.company_id == company1.id
sale = models.Sales(day='2013-02-02')
sale.data.append(models.SaleData(cash_start_of_day = 0, cash_end_of_day = 500000, income = 500000))
branch1.sales.append(sale)
db.session.commit()
assert sale.id is not None
if __name__ == '__main__':
unittest.main()
There may be bad practice in this model or unit test, and I will be delighted if you point that out :)
Thanks!
