">", "<", ">=" and "<=" don't work with "filter()" in Django

Question

With = below, I could filter persons by age:

qs = Person.objects.filter(age = 20)
                             # ↑ Here

But with >, <, >= and <= below, I couldn't filter persons by age:

qs = Person.objects.filter(age > 20)
                             # ↑ Here

qs = Person.objects.filter(age < 20)
                             # ↑ Here

qs = Person.objects.filter(age >= 20)
                             # ↑↑ Here

qs = Person.objects.filter(age <= 20)
                             # ↑↑ Here

Then, I got the error below:

NameError: name 'age' is not defined

How can I do greater than(>), greater than or equal to(>=), less than(<) and less than or equal to(>=) with filter() in Django?

@BéresBotond Although the docs look great - the structuring and layout is so poor that without a direct link, they are all but useless — RunLoop, Jul 06 '15 at 04:41
Working link for doc: https://docs.djangoproject.com/en/1.11/ref/models/querysets/#gt — Gaurav Pandey, Jan 24 '18 at 07:43

score 504 · Accepted Answer · edited Jan 11 '23 at 06:33

504

Greater than:

Person.objects.filter(age__gt=20)

Greater than or equal to:

Person.objects.filter(age__gte=20)

Less than:

Person.objects.filter(age__lt=20)

Less than or equal to:

Person.objects.filter(age__lte=20)

edited Jan 11 '23 at 06:33

answered Apr 06 '12 at 06:52

lprsd

2

Wow, that was fast :). This works great for less than or equal, but how about just less than? (userprofile__level__lt=3) doesn't seem to work – Finglish Apr 06 '12 at 06:57
1

It does; but in any case, you can also do exclude(__gte) instead of filter(__lt). – lprsd Apr 06 '12 at 07:01
5

And do NOT forget that there are two `__` underlines – andilabs Jan 30 '14 at 06:48
Im getting this error--> {FieldError}Unsupported lookup 'level' for AutoField or join on the field not permitted. – Aravind Pillai Sep 20 '18 at 03:18
question, what does =0 mean here? false? true? – DeyaEldeen Sep 23 '20 at 07:44
1

Remember change `userprofile__level` by your fields e.g. `youtfield__lte`. @AravindRPillai – christianbueno.1 Jul 03 '22 at 23:33

score 0 · Answer 2 · answered Jan 11 '23 at 06:31

Put __gt suffix for "Greater Than" to the field name age:

Person.objects.filter(age__gt=20)
                    #    ↑↑↑↑ 
                    # age > 20

Put __gte suffix for "Greater Than or Equal to" to the field name age:

Person.objects.filter(age__gte=20)
                    #    ↑↑↑↑↑ 
                    # age >= 20

Put __lt suffix for "Less Than" to the field name age:

Person.objects.filter(age__lt=20)
                    #    ↑↑↑↑ 
                    # age < 20

Put __lte suffix for "Less Than or Equal to" to the field name age:

Person.objects.filter(age__lte=20)
                    #    ↑↑↑↑↑ 
                    # age <= 20

2 Answers2