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2

I have an app for a Restaurant. And I have this model:

class Product(models.Model):
 name = models.CharField(max_length=50)
 price = models.PositiveIntegerField()

I have a list called TopSelled like this:

['Beer', 'Burger', ...]

I want to aggregate a boolean field called 'Hot', depending if product item is "top-sell" or not.

So my annotation should be something like this:

Product.objects.all().annotate(if Product.Name in List: HOT = True ELSE Hot = False)

How can I achieve this? Thx!

django django-orm

share|improve this question

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Won't it be better to just add a boolean field hot into your Product model? And then when you do Product.objects.all(), you can loop through the QuerySet and just change Product.hot = True.
  
  – Paolo
  Mar 25 at 20:30
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I already did what you suggested. But performance is not very good. I am trying to do this with Aggregate(avoid a For Loop) and compare performance. Thanks!
  
  – Matias Gatti
  Mar 25 at 20:38
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Oh great, thanks for your input! I didn't think about performance as much.
  
  – Paolo
  Mar 25 at 20:50
  

  
  
  
  

add a comment | 

2

I have an app for a Restaurant. And I have this model:

class Product(models.Model):
 name = models.CharField(max_length=50)
 price = models.PositiveIntegerField()

I have a list called TopSelled like this:

['Beer', 'Burger', ...]

I want to aggregate a boolean field called 'Hot', depending if product item is "top-sell" or not.

So my annotation should be something like this:

Product.objects.all().annotate(if Product.Name in List: HOT = True ELSE Hot = False)

How can I achieve this? Thx!

django django-orm

share|improve this question

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Won't it be better to just add a boolean field hot into your Product model? And then when you do Product.objects.all(), you can loop through the QuerySet and just change Product.hot = True.
  
  – Paolo
  Mar 25 at 20:30
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I already did what you suggested. But performance is not very good. I am trying to do this with Aggregate(avoid a For Loop) and compare performance. Thanks!
  
  – Matias Gatti
  Mar 25 at 20:38
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Oh great, thanks for your input! I didn't think about performance as much.
  
  – Paolo
  Mar 25 at 20:50
  

  
  
  
  

add a comment | 

I have an app for a Restaurant. And I have this model:

class Product(models.Model):
 name = models.CharField(max_length=50)
 price = models.PositiveIntegerField()

I have a list called TopSelled like this:

['Beer', 'Burger', ...]

I want to aggregate a boolean field called 'Hot', depending if product item is "top-sell" or not.

So my annotation should be something like this:

Product.objects.all().annotate(if Product.Name in List: HOT = True ELSE Hot = False)

How can I achieve this? Thx!

django django-orm

share|improve this question

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

class Product(models.Model):
 name = models.CharField(max_length=50)
 price = models.PositiveIntegerField()

['Beer', 'Burger', ...]

Product.objects.all().annotate(if Product.Name in List: HOT = True ELSE Hot = False)

share|improve this question

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

share|improve this question

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

edited Mar 30 at 8:19

Endre Both

3,17111 gold badge1313 silver badges2222 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

asked Mar 25 at 20:28

Matias GattiMatias Gatti

1333 bronze badges

1 Answer
1

active

oldest

votes

3

Try annotating with Case:

from django.db.models import BooleanField
from django.db.models.expressions import Case, When

Product.objects.annotate(hot=Case(
 When(name__in=hot_list, then=True), 
 output_field=BooleanField())
 ).filter(hot=True)

share|improve this answer

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This was exactly was I was looking for . Thanks !
  
  – Matias Gatti
  Mar 25 at 21:29
  

  
  
  
  

add a comment | 

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3

Try annotating with Case:

from django.db.models import BooleanField
from django.db.models.expressions import Case, When

Product.objects.annotate(hot=Case(
 When(name__in=hot_list, then=True), 
 output_field=BooleanField())
 ).filter(hot=True)

share|improve this answer

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This was exactly was I was looking for . Thanks !
  
  – Matias Gatti
  Mar 25 at 21:29
  

  
  
  
  

add a comment | 

3

Try annotating with Case:

from django.db.models import BooleanField
from django.db.models.expressions import Case, When

Product.objects.annotate(hot=Case(
 When(name__in=hot_list, then=True), 
 output_field=BooleanField())
 ).filter(hot=True)

share|improve this answer

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This was exactly was I was looking for . Thanks !
  
  – Matias Gatti
  Mar 25 at 21:29
  

  
  
  
  

add a comment | 

Try annotating with Case:

from django.db.models import BooleanField
from django.db.models.expressions import Case, When

Product.objects.annotate(hot=Case(
 When(name__in=hot_list, then=True), 
 output_field=BooleanField())
 ).filter(hot=True)

share|improve this answer

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges

from django.db.models import BooleanField
from django.db.models.expressions import Case, When

Product.objects.annotate(hot=Case(
 When(name__in=hot_list, then=True), 
 output_field=BooleanField())
 ).filter(hot=True)

share|improve this answer

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges

answered Mar 25 at 20:48

Endre BothEndre Both

3,17111 gold badge1313 silver badges2222 bronze badges