I have two classes:
class Order(models.Model):
...
date = models.DateTimeField(blank=True, verbose_name=u'Date add',default=datetime.now)
price = models.DecimalField(max_digits=7, decimal_places=2, verbose_name=u'Price', blank=True, null=True)
...
def __unicode__(self):
return "%s" % (self.date)
class OrderItem(models.Model):
...
date = models.DateTimeField(blank=True, verbose_name=u'Date add',default=datetime.now)
order = models.ForeignKey(Order, verbose_name=u'Order')
itemname = models.CharField(max_length=255, verbose_name=u'Item name')
quantity = models.PositiveIntegerField(default=1, verbose_name=u'Quantity')
price = models.DecimalField(max_digits=7, decimal_places=2, verbose_name=u'Price')
def __unicode__(self):
return "%s" % (self.itemname)
And I want to display orders with orderitems in list:
class OrderAdmin(admin.ModelAdmin):
list_display = ('price','<????>ORDERITEMS</????>')
How to do it?
It is a bit hard to do with your setup. If you use a related_name in your OrderItem model such as
order = models.ForeignKey(Order, related_name='items')
You could use it as a reference from the order to items. But again you have a OneToMany relationship so order have many items. You could crate a property in order to get you something like number_of_items such as
#property
def number_of_items(self):
return self.items.count()
and use that in the OrderAdmin such as
class OrderAdmin(admin.ModelAdmin):
list_display = ('price','number_of_items')
It is much easier if you are trying to access Order from OrderItem ModelAdmin because that returns one object so you could do:
class OrderItemAdmin(admin.ModelAdmin):
list_display = ('itemname',order__price')
note the use of double underscore between order and price.
I write this function to Order model:
def get_items(self):
text = ""
for i in self.oitems.all():
text = text + '<br />' + i.itemname
return text
get_items.allow_tags = True
And I add related_name="oitems" to Order Key in OrderItem. And it works.
Related
class Product(models.Model):
name = models.CharField(max_length=80)
product_image = models.ImageField(upload_to='product/product/images/%Y/%m/%d/', blank=True)
price = models.IntegerField()
class Cart(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True)
class CartItem(models.Model):
item = models.ForeignKey(Product, null=True, on_delete=models.CASCADE)
qty = models.IntegerField(default=1)
cart = models.ForeignKey(Cart, null=True, on_delete=models.CASCADE)
I'm trying to get an automatic total price that will be shown on check out page. I want to add a 'total_price' column on CartItem model and set the default 'item.price * qty', but when I tried to add this line to the class:
total_price = models.IntegerField(default=item.price)
since default value for qty is 1 but I got AttributeError: 'ForeignKey' object has no attribute 'price' error.
I also tried add this to the class:
#property
def total_price(self):
item = self.object.get(product=self.item)
return self.item.price
but I'm not sure which model will have the property? And when I added this method, I lost total_price column which I set its default as 0. I apologize for the lacking quality of solutions!
You are in right direction. You can try annotation or aggregation to get the total price. Here is one approach:
For all Cart Items using annotation with Sum:
Cart.objects.all().annotate(total_spent=Sum(
F('cartitem__item__price') *
F('cartitem__qty'),
output_field=models.FloatField()
))
For one Cart, you can try like this with aggregation:
class Cart(...):
....
#property
def total_price(self):
return self.cartitem_set.aggregate(price=Sum(
F('item__price') *
F('qty'),
output_field=models.FloatField()
)['price']
Change the total_price property to:
class CartItem(models.Model):
cart = models.ForeignKey(Cart, null=True, on_delete=models.CASCADE,
related_name="orders")
#property
def total_price(self):
return self.qty * self.item.price
And you can easily get the total price of the Order Item.
If you want to get Total amount of all CartItems prices can do like below:
class Cart(models.Model):
#property
def total_amount(self):
self.orders.annotate(total_spent=Sum(
F('item__price') *
F('qty'),
output_field=models.FloatField()
))
I have two models in different apps like so:
class Account(models.Model):
"""
Class to store fiat account information of a companies bank account
"""
number = models.CharField(max_length=100)
currency = models.ForeignKey(FiatCurrency, on_delete=models.CASCADE)
owner = models.ForeignKey(Company, on_delete=models.CASCADE)
date_added = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.number
class FiatTransaction(models.Model):
"""
Class to store Transactions made between escrow and operative white-listed fiat accounts
"""
debit_account = models.ForeignKey('company.Account', on_delete=models.CASCADE, related_name='debit_account')
credit_account = models.ForeignKey('company.Account', on_delete=models.CASCADE, related_name='credit_account')
executed_on = models.DateTimeField(auto_now_add=True)
amount = models.FloatField()
currency = debit_account.currency
is_processed = models.BooleanField(default=False)
fee = models.FloatField()
memo = models.CharField(max_length=250)
def __str__(self):
return F"Transferred {self.amount} from {self.debit_account} to {self.credit_account} at {self.executed_on}"
Now the field currency of model FiatTransaction doesn't seem to work the way I intend it to do. It raises
AttributeError: 'ForeignKey' object has no attribute 'currency'
# Source model
class FiatCurrency(models.Model):
"""
A model to store Fiat Currencies offered by Finchin to
include into cash-pools.
"""
ISO_Code = models.CharField(max_length=3)
name = models.CharField(max_length=50)
is_active = models.BooleanField(default=True)
def __str__(self):
return self.name
Why's that and how to make this work?
You can make a #property that will determine the currency of that object with:
class FiatTransaction(models.Model):
debit_account = models.ForeignKey('company.Account', on_delete=models.CASCADE, related_name='debit_account')
credit_account = models.ForeignKey('company.Account', on_delete=models.CASCADE, related_name='credit_account')
executed_on = models.DateTimeField(auto_now_add=True)
amount = models.FloatField()
is_processed = models.BooleanField(default=False)
fee = models.FloatField()
memo = models.CharField(max_length=250)
#property
def currency(self):
return self.debit_account.currency
This can however be inefficient if you have to do this for a lot of FiatTransactions.
In that case it might be better to remove the currency property, and annotate the QuerySet with:
from django.db.models import F
FiatTransaction.objects.annotate(currency=F('debit_account__currency'))
The FiatTransactions that arise from this will have an extra attribute named .currency that will contain the .currency of the .debit_account.
If you need this often, you can make use of a Manager that will automatically annotate when you access FiatTransaction.objects:
from django.db.models import F
class FiatTransactionManager(models.Manager):
def get_queryset(self, *args, **kwargs):
return super().get_queryset(*args, **kwargs).annotate(
currency=F('debit_account__currency')
)
class FiatTransaction(models.Model):
# …
objects = FiatTransactionManager()
I'd like to return a sum of fields (with #property) from a related model, that is itself the same type of sum (again using #property). I'm running into an issue that the Queryset that is being created in the ExpenseCategory model is either not iterable, or that the 'total_amount' is not a field in the related model (which is understandable). How should I approach this?
class ExpenseCategory(models.Model):
name = models.CharField(max_length=255, blank=False)
#property
def total_amount(self):
expenses = self.category_expenses.all()
return expenses.aggregate(Sum('total_amount'))
class ExpenseLineItem(models.Model):
category = models.ForeignKey(ExpenseCategory, related_name='category_expenses')
amount = models.DecimalField(max_digits=20, decimal_places=2, blank=True, default=0)
#property
def total_amount(self):
return self.amount
Order_by not working in FloatField type Django
models.py
class CourseCategory(models.Model):
category = models.CharField(max_length=100, unique=True, null=False)
description = models.TextField(blank=True)
class Meta(object):
app_label = "course_category"
def __unicode__(self):
return self.category
Coursetrack Model
class CourseTrack(models.Model):
category = models.ForeignKey(CourseCategory)
course_id = CourseKeyField(max_length=255, db_index=True)
tracks = models.FloatField(null=True, blank=True, default=None)
active = models.BooleanField(default=True)
class Meta(object):
app_label = "course_category"
def __unicode__(self):
return str(self.course_id)
TopCoursesCategory
class TopCoursesCategory(models.Model):
category = models.ForeignKey(CourseCategory)
class Meta(object):
app_label = "course_category"
def __unicode__(self):
return str(self.category)
I added here order_by(), as you can see but its not working.
view.py
def get_popular_courses_ids():
popular_category_id = CourseCategory.objects.filter(category='Popular')
popular_courses_ids = CourseTrack.objects.values('course_id').filter(category=popular_category_id).order_by('tracks')
course_id_list = []
for course_id in popular_courses_ids:
course_id_list.append(course_id['course_id'])
return course_id_list
I think the query you have posted is wrong.
You have used the following lines.
popular_category_id = CourseCategory.objects.filter(category='Popular')
popular_courses_ids = CourseTrack.objects.values('course_id').filter(category=popular_category_id).order_by('tracks')
In the first line, you have used filter and you have used the resulting variable as category= in your second query which you cannot do. For category= in your second query to work, you would need to give a single element and not a queryset. Replace your filter with get in the first query and it might work fine.
Or
If you think that popular_category_id can have more than one row for the category popular, leave the first query as it is and change your second query to
popular_courses_ids = CourseTrack.objects.values('course_id').filter(category__in=popular_category_id).order_by('tracks')
I have changed category to category__in.
First of all, please forgive for my newbie questions. I did copy most of the code, and try to understand from Django documents.
Code as below:
models.py
class Order(models.Model):
ORDER_CHOICES = (
('import', 'IMPORT'),
('export', 'EXPORT')
)
storage = models.ForeignKey(Storage, on_delete=models.PROTECT)
order_type = models.CharField(max_length=6, choices=ORDER_CHOICES)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now_add=True)
class Item(models.Model):
def random_barcode():
return str(random.randint(10000000, 99999999))
type = models.ForeignKey(Type, on_delete=models.CASCADE)
order = models.ForeignKey(Order, on_delete=models.CASCADE, null=True)
brand = models.ForeignKey(Brand, on_delete=models.CASCADE)
item_name = models.CharField(max_length=50, help_text='Name of goods, max 50 characters')
barcode = models.CharField(max_length=8, default=random_barcode, unique=True)
production_date = models.DateField()
expired_date = models.DateField()
def __str__(self):
return self.item_type
forms.py
class ItemForm(ModelForm):
class Meta:
model = Item
exclude = ['order',]
fields = ['type', 'brand', 'item_name', 'production_date', 'expired_date']
ItemFormSet = inlineformset_factory(Order, Item, form=ItemForm, extra=1)
views.py
class CreatePO(CreateView):
model = Order
context_object_name = 'orders'
template_name = 'storages/create_po.html'
fields = ['order_type', 'storage',]
*#dun't know how to write below code....*
1st question: how to use inline formset to write the CreatePO view?
2nd question: I need my create PO template as below picture, how to add a "Quantity" field?
This kind of template need Javascript, right? Any alternative solution? I have no knowledge with javascript.
First of all, move the def random_barcode(): before def __str__(self): it looks so ugly formated code.
Then let's have a look in your pic, if you haven't proper experience with Javascript you can use Admin Views from Django, it's much more simple and supported by Django 2.1. Read more if you would like to give permission to everyone in a admin-views page https://docs.djangoproject.com/el/2.1/releases/2.1/#model-view-permission
So quantity will be just added inside Item class
quantity = models.PositiveSmallIntegerField(default=1)
Also for your form, in my opinion, you need modelform_factory, so I suggest to read this one https://docs.djangoproject.com/en/2.1/topics/forms/modelforms/#modelform-factory-function