Query Expressions
Query Expressions
Query expressions describe a value or a computation that can be used as part of an update, create, filter, order by, annotation, or aggregate. There are a number of built-in expressions (documented below) that can be used to help you write queries. Expressions can be combined, or in some cases nested, to form more complex computations.
Support for using expressions when creating new model instances was added.
Supported arithmetic
Django supports addition, subtraction, multiplication, division, modulo arithmetic, and the power operator on query expressions, using Python constants, variables, and even other expressions.
Some examples
Some of the examples rely on functionality that is new in Django 1.8.
from django.db.models import F, Count, Value f