Django query case-insensitive list match

I have a list of names that I want to match case insensitive, is there a way to do it without using a loop like below?

a = ['name1', 'name2', 'name3']
result = any([Name.objects.filter(name__iexact=name) for name in a])

Solution 1:

Unfortunatley, there are no __iin field lookup. But there is a iregex that might be useful, like so:

result = Name.objects.filter(name__iregex=r'(name1|name2|name3)')

or even:

a = ['name1', 'name2', 'name3']
result = Name.objects.filter(name__iregex=r'(' + '|'.join(a) + ')')

Note that if a can contain characters that are special in a regex, you need to escape them properly.

NEWS: In Django 1.7+ it is possible to create your own lookups, so you can actually use filter(name__iin=['name1', 'name2', 'name3']) after proper initialization. See documentation reference for details.

Solution 2:

In Postgresql you could try creating a case insensitive index as described here:

https://stackoverflow.com/a/4124225/110274

Then run a query:

from django.db.models import Q
name_filter = Q()
for name in names:
    name_filter |= Q(name__iexact=name)
result = Name.objects.filter(name_filter)

Index search will run faster than the regex matching query.

Solution 3:

Another way to this using django query functions and annotation

from django.db.models.functions import Lower
Record.objects.annotate(name_lower=Lower('name')).filter(name_lower__in=['two', 'one']