class Now [source] New in Django 1.9. Returns the database server’s current date and time when the query is executed, typically using the SQL CURRENT_TIMESTAMP. Usage example: >>> from django.db.models.functions import Now >>> Article.objects.filter(published__lte=Now()) <QuerySet [<Article: How to Django>]> PostgreSQL considerations On PostgreSQL, the SQL CURRENT_TIMESTAMP returns the time that the current transaction started. Therefore for cross-database c

class Lower(expression, **extra) [source] Accepts a single text field or expression and returns the lowercase representation. It can also be registered as a transform as described in Length. Usage example: >>> from django.db.models.functions import Lower >>> Author.objects.create(name='Margaret Smith') >>> author = Author.objects.annotate(name_lower=Lower('name')).get() >>> print(author.name_lower) margaret smith Changed in Django 1.9: The ability to reg

class Length(expression, **extra) [source] Accepts a single text field or expression and returns the number of characters the value has. If the expression is null, then the length will also be null. Usage example: >>> # Get the length of the name and goes_by fields >>> from django.db.models.functions import Length >>> Author.objects.create(name='Margaret Smith') >>> author = Author.objects.annotate( ... name_length=Length('name'), ... goes_by_length=

class Least(*expressions, **extra) [source] New in Django 1.9. Accepts a list of at least two field names or expressions and returns the least value. Each argument must be of a similar type, so mixing text and numbers will result in a database error. Warning The behavior of Least when one or more expression may be null varies between databases: PostgreSQL: Least will return the smallest non-null expression, or null if all expressions are null. SQLite, Oracle, and MySQL: If any expression

class Greatest(*expressions, **extra) [source] New in Django 1.9. Accepts a list of at least two field names or expressions and returns the greatest value. Each argument must be of a similar type, so mixing text and numbers will result in a database error. Usage example: class Blog(models.Model): body = models.TextField() modified = models.DateTimeField(auto_now=True) class Comment(models.Model): body = models.TextField() modified = models.DateTimeField(auto_now=True)

class TruncYear(expression, output_field=None, tzinfo=None, **extra) [source] kind = 'year'

class TruncSecond(expression, output_field=None, tzinfo=None, **extra) [source] kind = 'second' These are logically equivalent to Trunc('datetime_field', kind). They truncate all parts of the date up to kind and allow grouping or filtering datetimes with less precision. expression must have an output_field of DateTimeField. Usage example: >>> from datetime import date, datetime >>> from django.db.models import Count >>> from django.db.models.functions import (

class TruncMonth(expression, output_field=None, tzinfo=None, **extra) [source] kind = 'month' These are logically equivalent to Trunc('date_field', kind). They truncate all parts of the date up to kind which allows grouping or filtering dates with less precision. expression can have an output_field of either DateField or DateTimeField. Since DateFields don’t have a time component, only Trunc subclasses that deal with date-parts can be used with DateField: >>> from datetime impo

class TruncMinute(expression, output_field=None, tzinfo=None, **extra) [source] kind = 'minute'

class TruncHour(expression, output_field=None, tzinfo=None, **extra) [source] kind = 'hour'