Django range

Summary: in this tutorial, you’ll learn how to use the Django range to check if a value is between two values.

A quick introduction to SQL BETWEEN operator #

In SQL, you use the BETWEEN operator to check if a value is between two values:

field_name BETWEEN low_value AND high_valueCode language: Python (python)

It’s equivalent to the following:

field_name >= low_value AND field_name <= high_valueCode language: Python (python)

The BETWEEN operator returns true if the field_name is between low_value and high_value. Otherwise, it returns False.

Using Django range with numbers #

Django’s equivalent of the BETWEEN operator is range:

Entity.objects.filter(field_name__range=(low_value,high_value))Code language: Python (python)

For example, you can find employees whose id is between 1 and 5 using the range like this:

>>> Employee.objects.filter(id__range=(1,5))Code language: Python (python)

Behind the scenes, Django executes the following query:

SELECT "hr_employee"."id",
       "hr_employee"."first_name",
       "hr_employee"."last_name",
       "hr_employee"."contact_id",
       "hr_employee"."department_id"
  FROM "hr_employee"
 WHERE "hr_employee"."id" BETWEEN 1 AND 5Code language: SQL (Structured Query Language) (sql)

Using Django range with dates #

Besides numbers and strings, the range also works with dates. For example, the following return all job assignments starting from January 1, 2020, to March 31, 2020:

>>> Assignment.objects.filter(begin_date__range=(start_date,end_date))      
SELECT "hr_assignment"."id",
       "hr_assignment"."employee_id",
       "hr_assignment"."job_id",
       "hr_assignment"."begin_date",
       "hr_assignment"."end_date"
  FROM "hr_assignment"
 WHERE "hr_assignment"."begin_date" BETWEEN '2020-01-01'::date AND '2020-03-31'::dateCode language: SQL (Structured Query Language) (sql)

NOT BETWEEN #

The NOT operator negates the BETWEEN operator:

field_name NOT BETWEEN (low_value, high_value)

In other words, the NOT BETWEEN returns true if a value is not in a range of values. It is equivalent to the following:

field_name < low_value OR field_value > high_valueCode language: Python (python)

In Django, you can use the Q object with the range to check if a value is not in a range:

Entity.objects.filter(~Q(field_name__range=(low_value,high_value)))Code language: Python (python)

For example, you can find employees with the id are not in the range (1,5):

>>> Employee.objects.filter(~Q(id__range=(1,5)))
SELECT "hr_employee"."id",
       "hr_employee"."first_name",
       "hr_employee"."last_name",
       "hr_employee"."contact_id",
       "hr_employee"."department_id"
  FROM "hr_employee"
 WHERE NOT ("hr_employee"."id" BETWEEN 1 AND 5)Code language: SQL (Structured Query Language) (sql)

Summary #

• Use the Django range to check if a value is in a range of values.