Questions about Django's Subquery expressions
Subquery expressions were added in Django 1.11.
Questions tagged [django-subquery]
30 questions
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
- 64
- 220
- 299
15
votes
2 answers
Django subquery and annotations with OuterRef
I'm having problems using annotate() with OuterRef in Django 1.11 subqueries. Example models:
class A(models.Model):
name = models.CharField(max_length=50)
class B(models.Model):
a = models.ForeignKey(A)
Now a query with a subquery (that…
toucan
- 1,465
- 1
- 17
- 31
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
- 9,888
- 6
- 52
- 73
11
votes
1 answer
Django subquery throws "more than one row returned by a subquery used as an expression"
I have recently upgraded to django 1.11 and I want to use the newly released, Subquery exrpession feature.
There are two models as follows
class Project(models.Model):
title = models.CharField(_("Project Name"), max_length=128)
class…
sajid
- 807
- 1
- 9
- 23
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
- 129
- 1
- 2
- 9
4
votes
1 answer
Django: Annotate list of related fields
I have an Company and User models with a related model CompanyRecruiter:
class CompanyRecruiter(models.Model):
organization = models.ForeignKey(Company, related_name="company_recruiters")
recruiter = models.ForeignKey(User,…
Martin Faucheux
- 884
- 9
- 26
3
votes
1 answer
Annotation with a subquery with multiple result in Django
I use postgresql database in my project and I use below example from django documentation.
from django.db.models import OuterRef, Subquery
newest =…
AlexMercer
- 301
- 3
- 10
2
votes
3 answers
Django with MySQL: 'Subquery returns more than 1 row'
Using django with a MySQL DB and given these models:
ModelB ---FK---> ModelA
- ref_type
- ref_id
ModelC
I want to get all the ModelC for each ModelA via an annotation.
I tried many options looking at existing solutions but could not…
Michael
- 8,357
- 20
- 58
- 86
2
votes
1 answer
Django: "missing 1 required positional argument: 'lookup _name'" when it is not missing?
I am working with Django 3.1 ORM and am running (with pytest) a test involving a complex nested query. I get this failure:
self =
lookup = 'lte'
def get_lookup(self,…
Lutz Prechelt
- 36,608
- 11
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- 88
2
votes
1 answer
How to limit top N of each group in Django ORM by using Postgres Window functions or Lateral Joins?
I have following Post, Category & PostScore Model.
class Post(models.Model):
category = models.ForeignKey('Category', on_delete=models.SET_NULL, related_name='category_posts', limit_choices_to={'parent_category': None}, blank=True, null=True)
…
Mahender Thakur
- 510
- 4
- 13
2
votes
1 answer
Summarized Subquery annotation with a filter by ForeignKey outer reference
I try to code the equivalent Django query from this SQL query, but I'm stuck.
Any help is welcome.
I receive a race id and from this race I want to do some statistics : nb_race = the number of races from a Horse before the race given, best_chrono =…
Frederic
- 115
- 10
2
votes
2 answers
How to perform a double step Subqueries in Django?
I have the below models:
class Group(models.Model):
group_name = models.CharField(max_length=32)
class Ledger(models.Model):
ledger_name = models.CharField(max_length=32)
group_name =…
Niladry Kar
- 1,163
- 4
- 20
- 50
1
vote
0 answers
Annotate GIS Intersection in Nested Subquery
I am trying to execute a complex Django query involving a nested subquery. Starting with the Stick model, I want to annotate the ownership_pct from the StickOwnership model (which is straightforward given the FK relationship). Next, I also want to…
Jeff Stewart
- 97
- 10
1
vote
1 answer
Performing a Subquery, Sum and Join in django ORM
I have 2 django models which aren't linked by ForeignKey due to legacy system.
class Parent(model):
name -> CharField()
class Child(model)
parent_name -> CharField()
cost -> IntegerField()
I want to achieve a left join which…
th3465
- 31
- 5
1
vote
1 answer
Updating fields via subquery in Django
I have an app with models and db schema that looks as shown below. I am trying to add field r to L2 in order to be able to access the related objects from model R. The new field is not shown in the schema figure.
Retrieving the desired value of…
m000
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