How to perform OR condition in django queryset?

user_633650 0
Viewed 246127

I want to write a Django query equivalent to this SQL query:

SELECT * from user where income >= 5000 or income is NULL.

How to construct the Django queryset filter?

User.objects.filter(income__gte=5000, income=0)

This doesn't work, because it ANDs the filters. I want to OR the filters to get union of individual querysets.

django-queryset django-orm django sql python
5 Answers

Both options are already mentioned in the existing answers:

from django.db.models import Q
q1 = User.objects.filter(Q(income__gte=5000) | Q(income__isnull=True))

and

q2 = User.objects.filter(income__gte=5000) | User.objects.filter(income__isnull=True)

However, there seems to be some confusion regarding which one is to prefer.

The point is that they are identical on the SQL level, so feel free to pick whichever you like!

The Django ORM Cookbook talks in some detail about this, here is the relevant part:

queryset = User.objects.filter(
        first_name__startswith='R'
    ) | User.objects.filter(
    last_name__startswith='D'
)

leads to

In [5]: str(queryset.query)
Out[5]: 'SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login",
"auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name",
"auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff",
"auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user"
WHERE ("auth_user"."first_name"::text LIKE R% OR "auth_user"."last_name"::text LIKE D%)'

and

qs = User.objects.filter(Q(first_name__startswith='R') | Q(last_name__startswith='D'))

leads to

In [9]: str(qs.query)
Out[9]: 'SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login",
 "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name",
  "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff",
  "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user"
  WHERE ("auth_user"."first_name"::text LIKE R% OR "auth_user"."last_name"::text LIKE D%)'

source: django-orm-cookbook

user_16229370

Just adding this for multiple filters attaching to Q object, if someone might be looking to it. If a Q object is provided, it must precede the definition of any keyword arguments. Otherwise its an invalid query. You should be careful when doing it.

an example would be

from django.db.models import Q
User.objects.filter(Q(income__gte=5000) | Q(income__isnull=True),category='income')

Here the OR condition and a filter with category of income is taken into account

user_102201840

In order to add the conditions like "OR" or "AND" as we kind of use in sql queries we have this way as an example

from django.db.models import Q
Poll.objects.get(Q(question__startswith='Who'),Q(pub_date=date(2005, 5, 2)) | Q(pub_date=date(2005, 5, 6)))

this is equivalent to this sql query

SELECT * from polls WHERE question LIKE 'Who%'
AND (pub_date = '2005-05-02' OR pub_date = '2005-05-06')

I hope you are able to understand this properly that the "," is for "AND" operator and "|" is for the "OR" operator used in django.

user_108741290
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