Sub query result in Django not looping from drop down select box - django

Question

This is the error am getting:
QuerySet.annotate() received non-expression(s): 17
What I want is a subquery that will do something similar to the
select * from inecdb.announced_pu_results
where polling_unit_uniqueid in
(
select uniqueid from polling_unit
where lga_id = (select uniqueid from lga where uniqueid= 17)
);
The subquery
obj3 = Pu_results.objects.filter(polling_unit_uniqueid__in=Subquery(Unit.objects.filter(lga_id=obj1)))
is not displaying any result please can any one help
This is my view
if request.method == 'POST':
selected_item = request.POST.get('item_id') #This is from html select box
obj = Lga.objects.get(lga_id=selected_item)
obj1 = obj.lga_id
obj3 = Pu_results.objects.filter(polling_unit_uniqueid__in=Subquery(Unit.objects.filter(lga_id=obj1)))
for obt in obj3:
print(obt.party_score) #I want looping results here
This is my Model
from django.db import models
from django.urls import reverse
#from django.urls import reverse
class Unit(models.Model):
uniqueid = models.IntegerField(primary_key=True)
polling_unit_id = models.IntegerField(blank=False)
ward_id = models.IntegerField(default=False)
lga_id = models.IntegerField(default=False)
uniquewardid = models.IntegerField(default=True)
polling_unit_number = models.CharField(max_length=50, unique=True)
polling_unit_name = models.CharField(max_length=51)
#pulling_unit_number = models.CharField(max_length=50)
polling_unit_description = models.CharField(max_length=300)
lat = models.CharField(max_length=255)
long = models.CharField(max_length=255)
entered_by_user = models.CharField(max_length=50)
date_entered = models.DateTimeField(blank=False)
user_ip_address = models.CharField(max_length=50)
def get_absolute_url(self):
#return f"/products/{self.id}/"
return reverse("polling:inec-pull-result", kwargs={"uniqueid": self.uniqueid})
class Lga(models.Model):
uniqueid = models.AutoField(primary_key=True)
lga_id = models.IntegerField()
lga_name = models.CharField(max_length=50)
state_id = models.IntegerField()
lga_description = models.TextField(blank=True, null=True)
entered_by_user = models.CharField(max_length=50)
date_entered = models.DateTimeField()
user_ip_address = models.CharField(max_length=50)
class Meta:
db_table = 'lga'
class Article(models.Model):
title = models.CharField(max_length=120)
content = models.TextField()
active = models.BooleanField(default=True)

Answer 1

You need to make sure that the queryset you use for the subquery returns just one column, use values() for that. Note that Subquery isn't needed:
units = Unit.objects.filter(lga_id=obj1).values('uniqueid')
obj3 = Pu_results.objects.filter(polling_unit_uniqueid__in=units)
Read the documentation for the in lookup for a more detailed explanation of passing a QuerySet to in.

Answer 2

This also works:
obj3 = Pu_results.objects.filter(
polling_unit_uniqueid__in = Subquery(
Unit.objects.values('uniqueid').filter(lga_id=obj1)
)
)