我正在创建一个销售点应用程序，具有典型的数据层次结构：Company->branches->Sales->SaleData，这是模型定义（请注意，用户模型已经准备好并作为烧瓶登录兼容模型工作） ：
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
现在，如果我尝试将销售数据添加到分支机构，那么如果我这样做就不会发生：
branch1 = company1.branches.filter().all()
我可以这样做：
branch1 = company1.branches[0]
如果不使用该[]运算符，我会收到错误消息：AttributeError: 'InstrumentedList' object has no attribute'。我已经在 SO 中浏览了另一个答案，它与lazybackref 定义中的内容有关，所以我已经修改了我当前的模型
但似乎我在这里遗漏了一些东西..有什么线索吗？谢谢！
编辑 1：添加了单元测试并添加了用户模型
我已经从 Mark Hildreth 那里得到了一个简洁的答案，它为我节省了很多！因此，我将把这个模型的完整单元测试放在这里。我相信它会帮助新手在 SQLAlchemy 的第一步。所以，这里是：
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()
此模型或单元测试中可能存在不良实践，如果您指出这一点，我会很高兴:)
谢谢！