using aggregate with values : group by : django - mysql

Question

i want to return a product names in distinct , and also i've used aggregate to some calculation as well
this is my models.py
class CustomerInvoice(models.Model):
customer = models.CharField(max_length=50)
items = models.ManyToManyField(Product,through='ProductSelecte')
date = models.DateTimeField(auto_now_add=True)
class ProductSelecte(models.Model):
product = models.ForeignKey(Product, on_delete=models.CASCADE)
products= models.ForeignKey(CustomerInvoice,on_delete=models.CASCADE,related_name='product')
qnt= models.IntegerField(default=1)
price = models.IntegerField()
cash = models.IntegerField()
i want to make table to track customers activity
and this is my query
context['clients'] = ProductSelecte.objects.filter(
products__customer=self.object.name).values('product').annotate(quantity=Sum(F('qnt'))).order_by('product')
till here works fine but i also need to aggregate price using this
.aggregate(
total_price=Sum(F('price')))
it raise this error
'dict' object has no attribute 'order_by'
thanks for your helping
UPDATE
for example at in first invoice of john 4th june john bought two pen price:20$ with 3 book price : 30$ total price for this invoice :50$ , and for second invoice 5th july he buy 1 pen price:10$ with 2 copybook price:20$ total price:30 , i need a result like this
client : john , activities : 3 pen(total pens he bought till now),price pens : 30 (total pens price he bought till now) , 3 book(total books he bought till now) ; price:30(total books price he bought till now) ,2 copybook ;price:20
and then total price of both invoice : 30+50 = 80

Answer 1

You should make the annotate per client per product and then perform some "grouping" at the Django/Python level:
from django.db.models import F, Sum
from itertools import groupby
from operator import itemgetter
qs = ProductSelecte.objects.values(
customer=F('products__customer')
product=F('product')
).annotate(quantity=Sum('qnt')).order_by('customer', 'product')
data = {
k: list(vs)
for k, vs in groupby(qs, itemgetter('customer'))
}
Here data is a dictionary that maps the name of the customer to a list of dictionaries that contain the id of the product, the customer name and the quantity.
If you pass it to the template, you can for example render this with:
<ul>
{% for c, vs in data.items %}
<li>{{ c }}</li>
<ul>
{% for v in vs %}
<li>{{ v.product }}: {{ v.quantity }}</li>
{% endfor %}
</ul>
{% endfor %}
</ul>
EDIT: based on the updated request, you should make an annotate and aggregate request:
class ProfileClientDetailView(LoginRequiredMixin,DetailView):
# …
def get_object(self):
return get_object_or_404(Client,pk=self.kwargs['pk'])
def get_context_data(self,*args,**kwargs):
data = super().get_context_data(*args,**kwargs)
data['products'] = ProductSelecte.objects.filter(
products__customer=self.object.name
).values('product').annotate(
quantity=Sum('qnt'),
total_price=Sum('price')
).order_by('product')
data['total'] = ProductSelecte.objects.filter(
products__customer=self.object.name
).aggregate(
quantity=Sum('qnt'),
total_price=Sum('price')
)
return data
Then it can be rendered as:
<ul>
{% for pr in products %}
<li>{{ pr.product }}: {{ pr.total_price }} ({{ pr.quantity }} items)</li>
</ul>
TOTAL: {{ total.total_price }} ({{ total.quantity }} items)