Questions tagged [django-annotate]
297 questions
188
votes
4 answers
aggregate() vs annotate() in Django
Django's QuerySet has two methods, annotate and aggregate. The documentation says that:
Unlike aggregate(), annotate() is not a terminal clause. The output of the annotate() clause is a…
Alexander Artemenko
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59
votes
7 answers
Django 1.11 Annotating a Subquery Aggregate
This is a bleeding-edge feature that I'm currently skewered upon and quickly bleeding out. I want to annotate a subquery-aggregate onto an existing queryset. Doing this before 1.11 either meant custom SQL or hammering the database. Here's the…
Oli
- 235,628
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28
votes
2 answers
How to subtract two annotated columns on Django QuerySets?
I need to be able to sort on the aggregate of two annotated columns
So I'd like to do something like this:
c = c.annotate(metric=Sum('results__metric'))
c = c.annotate(metric_prior=Sum('results__metric_prior'))
c =…
James R
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21
votes
2 answers
Django queryset annotate field to be a list/queryset
I'm trying to use django annotation to create queryset field which is a list of values of some related model attribute.
queryset = ...
qs = queryset.annotate(
list_field=SomeAggregateFunction(
Case(When(related_model__field="abc"),…
zyks
- 521
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17
votes
3 answers
How to concatenate two model fields in a Django QuerySet?
Consider a table called DataTable. It has two fields: A and B.
I want to return all rows from this table, and annotating a field called C which is a concatenation of A and B fields.
Here is what I have tried:
from django.db.models import CharField,…
yoyoyoyo123
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- 36
17
votes
3 answers
Django custom for complex Func (sql function)
In the process of finding a solution for Django ORM order by exact, I created a custom django Func:
from django.db.models import Func
class Position(Func):
function = 'POSITION'
template = "%(function)s(LOWER('%(substring)s') in…
Brown Bear
- 19,655
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15
votes
1 answer
Django - 'WhereNode' object has no attribute 'output_field' error
I am trying to query and annotate some data from my models:
class Feed(models.Model): # Feed of content
user = models.ForeignKey(User, on_delete=models.CASCADE)
class Piece(models.Model): # Piece of content (video or playlist)
…
Den Kasyanov
- 870
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14
votes
1 answer
Exclude null values from Django's ArrayAgg
I'm using Django's postgres-specific ArrayAgg aggregator. It works fine but when the list is empty I get [None] instead of []. Is there any way to filter these null values out? I've tried to pass a filter argument to ArrayAgg but it didn't work.…
Ariel
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12
votes
3 answers
Django conditional Subquery aggregate
An simplified example of my model structure would be
class Corporation(models.Model):
...
class Division(models.Model):
corporation = models.ForeignKey(Corporation)
class Department(models.Model):
division =…
Eldamir
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12
votes
1 answer
django - annotate() - Sum() of a column with filter on another column
I have the following two models.
class Product(models.Model):
product_group=models.ForeignKey('productgroup.ProductGroup', null=False,blank=False)
manufacturer=models.ForeignKey(Manufacturer, null=False,blank=False)
…
art
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12
votes
1 answer
Django's annotate Count with division returns integer instead of float
I have many objects and 3 of them have name='AAA'
I group them by 'name' and annotate num in group:
my_models = MyModel.objects.order_by('name').values('name').annotate(count=Count('name'))
for i in my_models:
print(i.count, i.name)
I get:
3,…
MaxCore
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9
votes
2 answers
Using Subquery to annotate a Count
Please help me I've been stuck on this for way too long :(
What I want to do:
I have these two models:
class Specialization(models.Model):
name = models.CharField("name", max_length=64)
class Doctor(models.Model):
name =…
Ysrninja
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9
votes
1 answer
Django annotate data by date for empty result
Suppose I have a object model A, and it has a field called created, which is a datetime type field.
If I use annotate to count how many A are created each day, I can use
A.objects.annotate(date=Trunc('created', 'day', output_field=DateField())…
Tiancheng Liu
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8
votes
1 answer
Django annotate count in JSONField with Postgres
Using Django I have a field which is of type JSONField. I am wanting to get a distinct count on a nested key/value in the json. With a normal field you can just do soemthing like the following …
ms18
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8
votes
1 answer
How to annotate the result of a model method to a django queryset
From the django docs on annotate():
Annotates each object in the QuerySet with the provided list of query
expressions. An expression may be a simple value, a reference to a
field on the model (or any related models), or...
Is it possible to…
43Tesseracts
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