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Django?????????ORM

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python manage.py runserver 0.0.0.0:80

????APP

python manage.py startapp sales

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python manage.py makemigrations common

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python manage.py migrate

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????????????????????????????customer?????????????????

class Customer(models.Model):
    name = models.CharField(max_length=200)
    phonenumber = models.CharField(max_length=200)
    address = models.CharField(max_length=200)
class Medicine(models.Model):
    name = models.CharField(max_length=200)
    sn = models.CharField(max_length=200)
    desc = models.CharField(max_length=200)
class Order(models.Model):
    name = models.CharField(max_length=200, null=True, blank=True)
    create_date = models.DateTimeField(default=datetime.datetime.now)
    customer = models.ForeignKey(Customer, on_delete=models.PROTECT)

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class Student(models.Model):
    name = models.CharField(max_length=200)
    classname = models.CharField(max_length=200)
    desc = models.CharField(max_length=200)
class ContactAddress(models.Model):
    student = models.OneToOneField(Student, on_delete=models.PROTECT)
    homeaddress = models.CharField(max_length=200)
    phone = models.CharField(max_length=200)

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class Order(models.Model):
    name = models.CharField(max_length=200, null=True, blank=True)
    create_date = models.DateTimeField(default=datetime.datetime.now)
    customer = models.ForeignKey(Customer, on_delete=models.PROTECT)
    medicines = models.ManyToManyField(Medicine, through='OrderMedicine')
class OrderMedicine(models.Model):
    order = models.ForeignKey(Order, on_delete=models.PROTECT)
    medicine = models.ForeignKey(Medicine, on_delete=models.PROTECT)
    amount = models.PositiveIntegerField()

ORM???????

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s1 = Student.objects.get(name='??')
s1.country.name

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Student.objects.filter(grade=1).values()

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cn = Country.objects.get(name='??')
cn.student_set.all()

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Country.objects.filter(students__grade=1).values()

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url????

urlpatterns = [
    path('customers', customer.dispatcher),
    path('medicines', medicine.dispatcher),
    path('orders', order.dispatcher),
    path('signin', sign_in_out.signin),
    path('signout', sign_in_out.signout),
]

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@transaction.atomic
def addorder(request):
    info = request.params['data']
    new_order = Order.objects.create(
        name=info['name'],
        customer_id=info['customerid']
    )
    batch = [
        OrderMedicine(order_id=new_order.id, medicine_id=mid, amount=1)
        for mid in info['medicineids']
    ]
    OrderMedicine.objects.bulk_create(batch)
    return JsonResponse({'ret': 0, 'id': new_order.id})

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def listorder(request):
    qs = Order.objects.values('id', 'name', 'create_date', 'customer__name', 'medicines__name')
    retlist = list(qs)
    return JsonResponse({'ret': 0, 'retlist': retlist})

????????????????????????Django??????????ORM???