I use Djongo package to connect to MongoDB from my Django app. However, there is inconsistency in the query results, even though not expected.

Here is my model:

class Item(models.Model):
    name = models.CharField(max_length=100)
    description = models.TextField()
    date = models.DateTimeField(db_index=True)
    port_inventory_id = models.IntegerField(db_index=True)

This query first filters by port_inventory_id, then date__range and returns the correct result

items = Item.objects.filter(port_inventory_id=999999).filter(date__range=(date_from, date_to))

However, this query first filters by date__range, then port_inventory_id and returns the same number of items without the filter(port_inventory_id=999999)

items = Item.objects.filter(date__range=(date_from, date_to)).filter(port_inventory_id=999999)

I also tried making one filter call with two filters

items = Item.objects.filter(date__range=(date_from, date_to), port_inventory_id=999999)

And also reverse

items = Item.objects.filter(port_inventory_id=999999, date__range=(date_from, date_to))

The only it works is this:

items = Item.objects.filter(port_inventory_id=999999).filter(date__range=(date_from, date_to))

I did not expect the result to change this way.

Any help is much appeciated…