Django aggregation with objects - django

model:
class Product(models.Model):
name = models.CharField(max_length = 128)
(...)
def __unicode__(self):
return self.name
class Receipt(models.Model):
name = models.CharField(max_length=128)
(...)
components = models.ManyToManyField(Product, through='ReceiptComponent')
def __unicode__(self):
return self.name
class ReceiptComponent(models.Model):
product = models.ForeignKey(Product)
receipt = models.ForeignKey(Receipt)
quantity = models.FloatField(max_length=9)
unit = models.ForeignKey(Unit)
def __unicode__(self):
return unicode(self.quantity!=0 and self.quantity or '') + ' ' + unicode(self.unit) + ' ' + self.product.genitive
And now I'd like to get list of the most often useable products:
ReceiptComponent.objects.values('product').annotate(Count('product')).order_by('-product__count'
the example result:
[{'product': 3, 'product__count': 5}, {'product': 6, 'product__count': 4}, {'product': 5, 'product__count': 3}, {'product': 7, 'product__count': 2}, {'product': 1, 'product__count': 2}, {'product': 11, 'product__count': 1}, {'product': 8, 'product__count': 1}, {'product': 4, 'product__count': 1}, {'product': 9, 'product__count': 1}]
It's almost what I need. But I'd prefer having Product object not product value, because I'd like to use this in views.py for generating list.

If I'm not mistaken this has the same behaviour but with objects?
Product.objects.all().annotate(usecount=Count('receipt_set')).order_by('-usecount')

Related

how to get only values from query dict

if request.method == 'POST':
product=request.POST.get('product')
upload_month = request.POST.get('upload_month')
un_month= Planning_quantity_data.objects.values('month').filter(product=product,upload_month=upload_month).distinct()
print(un_month)
<QuerySet [{'month': 'Mar_22'}, {'month': 'Apr_22'}, {'month': 'May_22'}, {'month': 'Jun_22'}]>
I want to get only the values without key and store it in a new list in
views.py file:
like newlist = ['Mar_22' , 'Apr_22', 'May_22','Jun_22']
while I am using
un_month1=list(un_month.values())
print(un_month1)
It is showing like something this:
[{'id': 1, 'upload_month': 'Mar_22', 'product': 'MAE675', 'material_code': 'MAE675 (MEMU â OB) RCF', 'order_type': 'Onhand', 'BOM_CODE': '675MEMU', 'month': 'Mar_22', 'quantity': 3, 'po_value': '37/5', 'remarks': 'Qty in Rakes. 3-5 rakes partial qty dispatched', 'empid': None}, {'id': 2, 'upload_month': 'Mar_22', 'product': 'MAE675', 'material_code': 'MAE675 (MEMU â OB) RCF', 'order_type': 'Onhand', 'BOM_CODE': '675MEMU', 'month': 'Apr_22', 'quantity': 3, 'po_value': '37/5', 'remarks': 'Qty in Rakes. 3-5 rakes partial qty dispatched', 'empid': None}, {'id': 3, 'upload_month': 'Mar_22', 'product': 'MAE675', 'material_code': 'MAE675 (MEMU â OB) RCF', 'order_type': 'Onhand', 'BOM_CODE': '675MEMU', 'month': 'May_22', 'quantity': 3, 'po_value': '37/5', 'remarks': 'Qty in Rakes. 3-5 rakes partial qty dispatched', 'empid': None}]
If you use values_list() [django-docs] with a single field, you can use flat=True to return a QuerySet of single values, I mean:
if request.method == 'POST':
product=request.POST.get('product')
upload_month = request.POST.get('upload_month')
newlist = list(Planning_quantity_data.objects.filter(product=product,upload_month=upload_month).values_list('month', flat=True))
print(newlist)
And this will print just ['Mar_22', 'Apr_22', 'May_22', 'Jun_22'] for you.

How to get the Primary key of annotate Count

Hi stackoverflow community, my question is about django annotate.
Basically what I am trying to do is to find duplicated value with same values from two different fields in two different tables.
This is my models.py
class Order(models.Model):
id_order = models.AutoField(primary_key=True)
class OrderDelivery(models.Model):
order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True, blank=True)
delivery_address = models.TextField()
class OrderPickup(models.Model):
order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True, blank=True)
pickup_date = models.DateField(blank=True, null=True)
This is my current code:
dup_job = Order.objects.filter(
orderpickup__pickup_date__range=(start_date, end_date)
).values(
'orderdelivery__delivery_address',
'orderpickup__pickup_date',
).annotate(
duplicated=Count('orderdelivery__delivery_address')
).filter(
duplicated__gt=1
)
Based on what I have, I am getting result like this (delivery_address is omitted for privacy purpose):
{'orderdelivery__delivery_address': '118A', 'orderpickup__pickup_date': datetime.date(2022, 3, 9), 'duplicated': 2}
{'orderdelivery__delivery_address': '11', 'orderpickup__pickup_date': datetime.date(2022, 3, 2), 'duplicated': 6}
{'orderdelivery__delivery_address': '11 A ', 'orderpickup__pickup_date': datetime.date(2022, 3, 3), 'duplicated': 5}
{'orderdelivery__delivery_address': '21', 'orderpickup__pickup_date': datetime.date(2022, 3, 10), 'duplicated': 3}
{'orderdelivery__delivery_address': '642', 'orderpickup__pickup_date': datetime.date(2022, 3, 7), 'duplicated': 2}
{'orderdelivery__delivery_address': '642', 'orderpickup__pickup_date': datetime.date(2022, 3, 8), 'duplicated': 2}
{'orderdelivery__delivery_address': 'N/A,5', 'orderpickup__pickup_date': datetime.date(2022, 3, 8), 'duplicated': 19}
Is there a way to get the id_order of those 'duplicated'?
I have tried include id_order in .values() but the output will not be accurate as the annotation is grouping by the id_order instead of delivery_address.
Thank you in advance
You can get the smallest (or largest) item with a Min [Django-doc] (or Max) aggregate:
from django.db.models import Min
dup_job = Order.objects.filter(
orderpickup__pickup_date__range=(start_date, end_date)
).values(
'orderdelivery__delivery_address',
'orderpickup__pickup_date',
).annotate(
min_id_order=Min('id_order')
duplicated=Count('orderdelivery__delivery_address')
).filter(
duplicated__gt=1
)
or for postgresql, you can make use of the ArrayAgg [Django-doc] to generate a list:
# PostgreSQL only
from django.contrib.postgres.aggregates import ArrayAgg
dup_job = Order.objects.filter(
orderpickup__pickup_date__range=(start_date, end_date)
).values(
'orderdelivery__delivery_address',
'orderpickup__pickup_date',
).annotate(
min_id_order=ArrayAgg('id_order')
duplicated=Count('orderdelivery__delivery_address')
).filter(
duplicated__gt=1
)

Get number of objects in serializer where foreign key field is x

Suppose
class ABC(models.Models):
...
id = models.SlugField(...)
user = models.ForeignKey(settings.AUTH_USER_MODEL)
...
Now i want something like
[{id: adfsdd, no_of_user_objects: 5}, {id: gdfvsdf, no_of_user_objects: 0}, {id: ergthf, no_of_user_objects: 2}]
How do i achieve this?
Model method for getting the number of users having the same slug id:
class ABC(models.Models):
...
id = models.SlugField(...)
user = models.ForeignKey(settings.AUTH_USER_MODEL)
...
#property # for using in serializer
def no_of_user_objects(self):
return ABC.objects.filter(id=self.id).count()
And in your serializer have a custom serializer for the queryset serializer:
class ABDSerializer(serializers.ModelSerializer):
class Meta:
model = ABC
fields = ['id', 'no_of_user_objects']
# in your view
queryset = ABC.objects.distinct('id')
serializer = ABDSerializer(queryset, many=True)
print(serializer.data)
# get you [{id: adfsdd, no_of_user_objects: 5}, {id: gdfvsdf, #no_of_user_objects: 0}, {id: ergthf, no_of_user_objects: 2}]

Django Query month wise with last 6 month

I am trying to query and the group is the Order of the last 6 months.
and this is my models:
class Order(models.Model):
created_on = models.DateTimeField(_("Created On"), auto_now_add=True)
and this is my method to parse month:
from django.db.models import Func
class Month(Func):
"""
Method to extract month
"""
function = 'EXTRACT'
template = '%(function)s(MONTH from %(expressions)s)'
output_field = models.IntegerField()
And this is my query:
current_date = date.today()
months_ago = 6
six_month_previous_date = current_date - timedelta(days=(months_ago * 365 / 12))
order = Order.objects.filter(
created_on__gte=six_month_previous_date,
).annotate(
month=Month('created_on')
).values(
'month'
).annotate(
count=Count('id')
).values(
'month',
'count'
).order_by(
'month'
)
In my database order table, there is only on entry:
So it is returning
[{'month': 10, 'count': 1}]
But i dont want like this, i want like these of last 6 month, if in one month, there is no sales, it should return the count: 0
Like thise bellow:
[
{'month': 10, 'count': 1},
{'month': 9, 'count': 0}
{'month': 8, 'count': 0}
{'month': 7, 'count': 0}
{'month': 6, 'count': 0}
{'month': 5, 'count': 0}
]
A database works under the closed world assumption, so it will not insert rows with 0. You can however post-process the list.
from django.utils.timezone import now
order = Order.objects.filter(
created_on__gte=six_month_previous_date,
).values(
month=Month('created_on')
).annotate(
count=Count('id')
).order_by('month')
order = {r['month']: r['count'] for r in order}
month = now().month
result = [
{'month': (m % 12)+1, 'count': order.get((m % 12) + 1, 0)}
for m in range(month-1, month-8, -1)
]
Note that Django already has an ExtractMonth function [Django-doc].

How to set ordering and number of items for each item in filter list?

How to set ordering and number of items for each item in filter list?
class Category(models.Model):
category = models.CharField(max_length = 20)
Class Question(TimeStampedModel):
category = models.ForeignKey(Category, related_name='question_set', on_delete=models.CASCADE)
question = models.TextField(_('Question Text'))
Category.objects.filter(category__in=['Sport', 'History']).values_list('question_set',flat=True).order_by('?')[:3]
<QuerySet [6, 7, 3]>
I need result like:
<QuerySet [1, 3, 2, 7, 11, 9]>