Refs #28643 -- Added math database functions.

Thanks Nick Pope for much review.

django/db/backends/sqlite3/base.py

@@ -173,10 +173,28 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         conn.create_function("django_timestamp_diff", 2, _sqlite_timestamp_diff)
         conn.create_function("regexp", 2, _sqlite_regexp)
         conn.create_function("django_format_dtdelta", 3, _sqlite_format_dtdelta)
-        conn.create_function("django_power", 2, _sqlite_power)
         conn.create_function('LPAD', 3, _sqlite_lpad)
         conn.create_function('REPEAT', 2, operator.mul)
         conn.create_function('RPAD', 3, _sqlite_rpad)
+        conn.create_function('ACOS', 1, math.acos)
+        conn.create_function('ASIN', 1, math.asin)
+        conn.create_function('ATAN', 1, math.atan)
+        conn.create_function('ATAN2', 2, math.atan2)
+        conn.create_function('CEILING', 1, math.ceil)
+        conn.create_function('COS', 1, math.cos)
+        conn.create_function('COT', 1, lambda x: 1 / math.tan(x))
+        conn.create_function('DEGREES', 1, math.degrees)
+        conn.create_function('EXP', 1, math.exp)
+        conn.create_function('FLOOR', 1, math.floor)
+        conn.create_function('LN', 1, math.log)
+        conn.create_function('LOG', 2, lambda x, y: math.log(y, x))
+        conn.create_function('MOD', 2, math.fmod)
+        conn.create_function('PI', 0, lambda: math.pi)
+        conn.create_function('POWER', 2, operator.pow)
+        conn.create_function('RADIANS', 1, math.radians)
+        conn.create_function('SIN', 1, math.sin)
+        conn.create_function('SQRT', 1, math.sqrt)
+        conn.create_function('TAN', 1, math.tan)
         conn.execute('PRAGMA foreign_keys = ON')
         return conn
 
@@ -483,7 +501,3 @@ def _sqlite_lpad(text, length, fill_text):
 
 def _sqlite_rpad(text, length, fill_text):
     return (text + fill_text * length)[:length]
-
-
-def _sqlite_power(x, y):
-    return x ** y

django/db/backends/sqlite3/operations.py

@@ -273,10 +273,10 @@ class DatabaseOperations(BaseDatabaseOperations):
         )
 
     def combine_expression(self, connector, sub_expressions):
-        # SQLite doesn't have a power function, so we fake it with a
+        # SQLite doesn't have a ^ operator, so use the user-defined POWER
-        # user-defined function django_power that's registered in connect().
+        # function that's registered in connect().
         if connector == '^':
-            return 'django_power(%s)' % ','.join(sub_expressions)
+            return 'POWER(%s)' % ','.join(sub_expressions)
         return super().combine_expression(connector, sub_expressions)
 
     def combine_duration_expression(self, connector, sub_expressions):

django/db/models/functions/__init__.py

@@ -5,6 +5,10 @@ from .datetime import (
     Now, Trunc, TruncDate, TruncDay, TruncHour, TruncMinute, TruncMonth,
     TruncQuarter, TruncSecond, TruncTime, TruncWeek, TruncYear,
 )
+from .math import (
+    Abs, ACos, ASin, ATan, ATan2, Ceil, Cos, Cot, Degrees, Exp, Floor, Ln, Log,
+    Mod, Pi, Power, Radians, Round, Sin, Sqrt, Tan,
+)
 from .text import (
     Chr, Concat, ConcatPair, Left, Length, Lower, LPad, LTrim, Ord, Repeat,
     Replace, Right, RPad, RTrim, StrIndex, Substr, Trim, Upper,
@@ -23,6 +27,10 @@ __all__ = [
     'ExtractYear', 'Now', 'Trunc', 'TruncDate', 'TruncDay', 'TruncHour',
     'TruncMinute', 'TruncMonth', 'TruncQuarter', 'TruncSecond', 'TruncTime',
     'TruncWeek', 'TruncYear',
+    # math
+    'Abs', 'ACos', 'ASin', 'ATan', 'ATan2', 'Ceil', 'Cos', 'Cot', 'Degrees',
+    'Exp', 'Floor', 'Ln', 'Log', 'Mod', 'Pi', 'Power', 'Radians', 'Round',
+    'Sin', 'Sqrt', 'Tan',
     # text
     'Chr', 'Concat', 'ConcatPair', 'Left', 'Length', 'Lower', 'LPad', 'LTrim',
     'Ord', 'Repeat', 'Replace', 'Right', 'RPad', 'RTrim', 'StrIndex', 'Substr',

django/db/models/functions/math.py

@@ -0,0 +1,174 @@
+import math
+import sys
+
+from django.db.models import (
+    DecimalField, FloatField, Func, IntegerField, Transform,
+)
+from django.db.models.functions import Cast
+
+
+class DecimalInputMixin:
+
+    def as_postgresql(self, compiler, connection):
+        # Cast FloatField to DecimalField as PostgreSQL doesn't support the
+        # following function signatures:
+        # - LOG(double, double)
+        # - MOD(double, double)
+        output_field = DecimalField(decimal_places=sys.float_info.dig, max_digits=1000)
+        clone = self.copy()
+        clone.set_source_expressions([
+            Cast(expression, output_field) if isinstance(expression.output_field, FloatField)
+            else expression for expression in self.get_source_expressions()
+        ])
+        return clone.as_sql(compiler, connection)
+
+
+class OutputFieldMixin:
+
+    def _resolve_output_field(self):
+        has_decimals = any(isinstance(s.output_field, DecimalField) for s in self.get_source_expressions())
+        return DecimalField() if has_decimals else FloatField()
+
+
+class Abs(Transform):
+    function = 'ABS'
+    lookup_name = 'abs'
+
+
+class ACos(OutputFieldMixin, Transform):
+    function = 'ACOS'
+    lookup_name = 'acos'
+
+
+class ASin(OutputFieldMixin, Transform):
+    function = 'ASIN'
+    lookup_name = 'asin'
+
+
+class ATan(OutputFieldMixin, Transform):
+    function = 'ATAN'
+    lookup_name = 'atan'
+
+
+class ATan2(OutputFieldMixin, Func):
+    function = 'ATAN2'
+    arity = 2
+
+    def as_sqlite(self, compiler, connection):
+        if not getattr(connection.ops, 'spatialite', False) or connection.ops.spatial_version < (4, 3, 0):
+            return self.as_sql(compiler, connection)
+        # This function is usually ATan2(y, x), returning the inverse tangent
+        # of y / x, but it's ATan2(x, y) on SpatiaLite 4.3+.
+        # Cast integers to float to avoid inconsistent/buggy behavior if the
+        # arguments are mixed between integer and float or decimal.
+        # https://www.gaia-gis.it/fossil/libspatialite/tktview?name=0f72cca3a2
+        clone = self.copy()
+        clone.set_source_expressions([
+            Cast(expression, FloatField()) if isinstance(expression.output_field, IntegerField)
+            else expression for expression in self.get_source_expressions()[::-1]
+        ])
+        return clone.as_sql(compiler, connection)
+
+
+class Ceil(Transform):
+    function = 'CEILING'
+    lookup_name = 'ceil'
+
+    def as_oracle(self, compiler, connection):
+        return super().as_sql(compiler, connection, function='CEIL')
+
+
+class Cos(OutputFieldMixin, Transform):
+    function = 'COS'
+    lookup_name = 'cos'
+
+
+class Cot(OutputFieldMixin, Transform):
+    function = 'COT'
+    lookup_name = 'cot'
+
+    def as_oracle(self, compiler, connection):
+        return super().as_sql(compiler, connection, template='(1 / TAN(%(expressions)s))')
+
+
+class Degrees(OutputFieldMixin, Transform):
+    function = 'DEGREES'
+    lookup_name = 'degrees'
+
+    def as_oracle(self, compiler, connection):
+        return super().as_sql(compiler, connection, template='((%%(expressions)s) * 180 / %s)' % math.pi)
+
+
+class Exp(OutputFieldMixin, Transform):
+    function = 'EXP'
+    lookup_name = 'exp'
+
+
+class Floor(Transform):
+    function = 'FLOOR'
+    lookup_name = 'floor'
+
+
+class Ln(OutputFieldMixin, Transform):
+    function = 'LN'
+    lookup_name = 'ln'
+
+
+class Log(DecimalInputMixin, OutputFieldMixin, Func):
+    function = 'LOG'
+    arity = 2
+
+    def as_sqlite(self, compiler, connection):
+        if not getattr(connection.ops, 'spatialite', False):
+            return self.as_sql(compiler, connection)
+        # This function is usually Log(b, x) returning the logarithm of x to
+        # the base b, but on SpatiaLite it's Log(x, b).
+        clone = self.copy()
+        clone.set_source_expressions(self.get_source_expressions()[::-1])
+        return clone.as_sql(compiler, connection)
+
+
+class Mod(DecimalInputMixin, OutputFieldMixin, Func):
+    function = 'MOD'
+    arity = 2
+
+
+class Pi(OutputFieldMixin, Func):
+    function = 'PI'
+    arity = 0
+
+    def as_oracle(self, compiler, connection):
+        return super().as_sql(compiler, connection, template=str(math.pi))
+
+
+class Power(OutputFieldMixin, Func):
+    function = 'POWER'
+    arity = 2
+
+
+class Radians(OutputFieldMixin, Transform):
+    function = 'RADIANS'
+    lookup_name = 'radians'
+
+    def as_oracle(self, compiler, connection):
+        return super().as_sql(compiler, connection, template='((%%(expressions)s) * %s / 180)' % math.pi)
+
+
+class Round(Transform):
+    function = 'ROUND'
+    lookup_name = 'round'
+
+
+class Sin(OutputFieldMixin, Transform):
+    function = 'SIN'
+    lookup_name = 'sin'
+
+
+class Sqrt(OutputFieldMixin, Transform):
+    function = 'SQRT'
+    lookup_name = 'sqrt'
+
+
+class Tan(OutputFieldMixin, Transform):
+    function = 'TAN'
+    lookup_name = 'tan'

docs/ref/models/database-functions.txt

@@ -673,6 +673,463 @@ that deal with time-parts can be used with ``TimeField``::
     2014-06-16 00:00:00+10:00 2
     2016-01-01 04:00:00+11:00 1
 
+.. _math-functions:
+
+Math Functions
+==============
+
+.. versionadded:: 2.2
+
+We'll be using the following model in math function examples::
+
+    class Vector(models.Model):
+        x = models.FloatField()
+        y = models.FloatField()
+
+``Abs``
+-------
+
+.. class:: Abs(expression, **extra)
+
+Returns the absolute value of a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Abs
+    >>> Vector.objects.create(x=-0.5, y=1.1)
+    >>> vector = Vector.objects.annotate(x_abs=Abs('x'), y_abs=Abs('y')).get()
+    >>> vector.x_abs, vector.y_abs
+    (0.5, 1.1)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Abs
+    >>> FloatField.register_lookup(Abs)
+    >>> # Get vectors inside the unit cube
+    >>> vectors = Vector.objects.filter(x__abs__lt=1, y__abs__lt=1)
+
+``ACos``
+--------
+
+.. class:: ACos(expression, **extra)
+
+Returns the arccosine of a numeric field or expression. The expression value
+must be within the range -1 to 1.
+
+Usage example::
+
+    >>> from django.db.models.functions import ACos
+    >>> Vector.objects.create(x=0.5, y=-0.9)
+    >>> vector = Vector.objects.annotate(x_acos=ACos('x'), y_acos=ACos('y')).get()
+    >>> vector.x_acos, vector.y_acos
+    (1.0471975511965979, 2.6905658417935308)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import ACos
+    >>> FloatField.register_lookup(ACos)
+    >>> # Get vectors whose arccosine is less than 1
+    >>> vectors = Vector.objects.filter(x__acos__lt=1, y__acos__lt=1)
+
+``ASin``
+--------
+
+.. class:: ASin(expression, **extra)
+
+Returns the arcsine of a numeric field or expression. The expression value must
+be in the range -1 to 1.
+
+Usage example::
+
+    >>> from django.db.models.functions import ASin
+    >>> Vector.objects.create(x=0, y=1)
+    >>> vector = Vector.objects.annotate(x_asin=ASin('x'), y_asin=ASin('y')).get()
+    >>> vector.x_asin, vector.y_asin
+    (0.0, 1.5707963267948966)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import ASin
+    >>> FloatField.register_lookup(ASin)
+    >>> # Get vectors whose arcsine is less than 1
+    >>> vectors = Vector.objects.filter(x__asin__lt=1, y__asin__lt=1)
+
+``ATan``
+--------
+
+.. class:: ATan(expression, **extra)
+
+Returns the arctangent of a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import ATan
+    >>> Vector.objects.create(x=3.12, y=6.987)
+    >>> vector = Vector.objects.annotate(x_atan=ATan('x'), y_atan=ATan('y')).get()
+    >>> vector.x_atan, vector.y_atan
+    (1.2606282660069106, 1.428638798133829)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import ATan
+    >>> FloatField.register_lookup(ATan)
+    >>> # Get vectors whose arctangent is less than 2
+    >>> vectors = Vector.objects.filter(x__atan__lt=2, y__atan__lt=2)
+
+``ATan2``
+---------
+
+.. class:: ATan2(expression1, expression2, **extra)
+
+Returns the arctangent of ``expression1 / expression2``.
+
+Usage example::
+
+    >>> from django.db.models.functions import ATan2
+    >>> Vector.objects.create(x=2.5, y=1.9)
+    >>> vector = Vector.objects.annotate(atan2=ATan2('x', 'y')).get()
+    >>> vector.atan2
+    0.9209258773829491
+
+``Ceil``
+--------
+
+.. class:: Ceil(expression, **extra)
+
+Returns the smallest integer greater than or equal to a numeric field or
+expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Ceil
+    >>> Vector.objects.create(x=3.12, y=7.0)
+    >>> vector = Vector.objects.annotate(x_ceil=Ceil('x'), y_ceil=Ceil('y')).get()
+    >>> vector.x_ceil, vector.y_ceil
+    (4.0, 7.0)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Ceil
+    >>> FloatField.register_lookup(Ceil)
+    >>> # Get vectors whose ceil is less than 10
+    >>> vectors = Vector.objects.filter(x__ceil__lt=10, y__ceil__lt=10)
+
+``Cos``
+-------
+
+.. class:: Cos(expression, **extra)
+
+Returns the cosine  of a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Cos
+    >>> Vector.objects.create(x=-8.0, y=3.1415926)
+    >>> vector = Vector.objects.annotate(x_cos=Cos('x'), y_cos=Cos('y')).get()
+    >>> vector.x_cos, vector.y_cos
+    (-0.14550003380861354, -0.9999999999999986)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Cos
+    >>> FloatField.register_lookup(Cos)
+    >>> # Get vectors whose cosine is less than 0.5
+    >>> vectors = Vector.objects.filter(x__cos__lt=0.5, y__cos__lt=0.5)
+
+``Cot``
+-------
+
+.. class:: Cot(expression, **extra)
+
+Returns the cotangent of a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Cot
+    >>> Vector.objects.create(x=12.0, y=1.0)
+    >>> vector = Vector.objects.annotate(x_cot=Cot('x'), y_cot=Cot('y')).get()
+    >>> vector.x_cot, vector.y_cot
+    (-1.5726734063976826, 0.642092615934331)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Cot
+    >>> FloatField.register_lookup(Cot)
+    >>> # Get vectors whose cotangent is less than 1
+    >>> vectors = Vector.objects.filter(x__cot__lt=1, y__cot__lt=1)
+
+``Degrees``
+-----------
+
+.. class:: Degrees(expression, **extra)
+
+Converts a numeric field or expression from radians to degrees.
+
+Usage example::
+
+    >>> from django.db.models.functions import Degrees
+    >>> Vector.objects.create(x=-1.57, y=3.14)
+    >>> vector = Vector.objects.annotate(x_d=Degrees('x'), y_d=Degrees('y')).get()
+    >>> vector.x_d, vector.y_d
+    (-89.95437383553924, 179.9087476710785)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Degrees
+    >>> FloatField.register_lookup(Degrees)
+    >>> # Get vectors whose degrees are less than 360
+    >>> vectors = Vector.objects.filter(x__degrees__lt=360, y__degrees__lt=360)
+
+``Exp``
+-------
+
+.. class:: Exp(expression, **extra)
+
+Returns the value of ``e`` (the natural logarithm base) raised to the power of
+a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Exp
+    >>> Vector.objects.create(x=5.4, y=-2.0)
+    >>> vector = Vector.objects.annotate(x_exp=Exp('x'), y_exp=Exp('y')).get()
+    >>> vector.x_exp, vector.y_exp
+    (221.40641620418717, 0.1353352832366127)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Exp
+    >>> FloatField.register_lookup(Exp)
+    >>> # Get vectors whose exp() is greater than 10
+    >>> vectors = Vector.objects.filter(x__exp__gt=10, y__exp__gt=10)
+
+``Floor``
+---------
+
+.. class:: Floor(expression, **extra)
+
+Returns the largest integer value not greater than a numeric field or
+expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Floor
+    >>> Vector.objects.create(x=5.4, y=-2.3)
+    >>> vector = Vector.objects.annotate(x_floor=Floor('x'), y_floor=Floor('y')).get()
+    >>> vector.x_floor, vector.y_floor
+    (5.0, -3.0)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Floor
+    >>> FloatField.register_lookup(Floor)
+    >>> # Get vectors whose floor() is greater than 10
+    >>> vectors = Vector.objects.filter(x__floor__gt=10, y__floor__gt=10)
+
+``Ln``
+------
+
+.. class:: Ln(expression, **extra)
+
+Returns the natural logarithm a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Ln
+    >>> Vector.objects.create(x=5.4, y=233.0)
+    >>> vector = Vector.objects.annotate(x_ln=Ln('x'), y_ln=Ln('y')).get()
+    >>> vector.x_ln, vector.y_ln
+    (1.6863989535702288, 5.4510384535657)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Ln
+    >>> FloatField.register_lookup(Ln)
+    >>> # Get vectors whose value greater than e
+    >>> vectors = Vector.objects.filter(x__ln__gt=1, y__ln__gt=1)
+
+``Log``
+-------
+
+.. class:: Log(expression1, expression2, **extra)
+
+Accepts two numeric fields or expressions and returns the logarithm of
+the first to base of the second.
+
+Usage example::
+
+    >>> from django.db.models.functions import Log
+    >>> Vector.objects.create(x=2.0, y=4.0)
+    >>> vector = Vector.objects.annotate(log=Log('x', 'y')).get()
+    >>> vector.log
+    2.0
+
+``Mod``
+-------
+
+.. class:: Mod(expression1, expression2, **extra)
+
+Accepts two numeric fields or expressions and returns the remainder of
+the first divided by the second (modulo operation).
+
+Usage example::
+
+    >>> from django.db.models.functions import Mod
+    >>> Vector.objects.create(x=5.4, y=2.3)
+    >>> vector = Vector.objects.annotate(mod=Mod('x', 'y')).get()
+    >>> vector.mod
+    0.8
+
+``Pi``
+------
+
+.. class:: Pi(**extra)
+
+Returns the value of the mathematical constant ``π``.
+
+``Power``
+---------
+
+.. class:: Power(expression1, expression2, **extra)
+
+Accepts two numeric fields or expressions and returns the value of the first
+raised to the power of the second.
+
+Usage example::
+
+    >>> from django.db.models.functions import Power
+    >>> Vector.objects.create(x=2, y=-2)
+    >>> vector = Vector.objects.annotate(power=Power('x', 'y')).get()
+    >>> vector.power
+    0.25
+
+``Radians``
+-----------
+
+.. class:: Radians(expression, **extra)
+
+Converts a numeric field or expression from degrees to radians.
+
+Usage example::
+
+    >>> from django.db.models.functions import Radians
+    >>> Vector.objects.create(x=-90, y=180)
+    >>> vector = Vector.objects.annotate(x_r=Radians('x'), y_r=Radians('y')).get()
+    >>> vector.x_r, vector.y_r
+    (-1.5707963267948966, 3.141592653589793)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Radians
+    >>> FloatField.register_lookup(Radians)
+    >>> # Get vectors whose radians are less than 1
+    >>> vectors = Vector.objects.filter(x__radians__lt=1, y__radians__lt=1)
+
+``Round``
+---------
+
+.. class:: Round(expression, **extra)
+
+Rounds a numeric field or expression to the nearest integer. Whether half
+values are rounded up or down depends on the database.
+
+Usage example::
+
+    >>> from django.db.models.functions import Round
+    >>> Vector.objects.create(x=5.4, y=-2.3)
+    >>> vector = Vector.objects.annotate(x_r=Round('x'), y_r=Round('y')).get()
+    >>> vector.x_r, vector.y_r
+    (5.0, -2.0)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Round
+    >>> FloatField.register_lookup(Round)
+    >>> # Get vectors whose round() is less than 20
+    >>> vectors = Vector.objects.filter(x__round__lt=20, y__round__lt=20)
+
+``Sin``
+-------
+
+.. class:: Sin(expression, **extra)
+
+Returns the sine of a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Sin
+    >>> Vector.objects.create(x=5.4, y=-2.3)
+    >>> vector = Vector.objects.annotate(x_sin=Sin('x'), y_sin=Sin('y')).get()
+    >>> vector.x_sin, vector.y_sin
+    (-0.7727644875559871, -0.7457052121767203)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Sin
+    >>> FloatField.register_lookup(Sin)
+    >>> # Get vectors whose sin() is less than 0
+    >>> vectors = Vector.objects.filter(x__sin__lt=0, y__sin__lt=0)
+
+``Sqrt``
+--------
+
+.. class:: Sqrt(expression, **extra)
+
+Returns the square root of a nonnegative numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Sqrt
+    >>> Vector.objects.create(x=4.0, y=12.0)
+    >>> vector = Vector.objects.annotate(x_sqrt=Sqrt('x'), y_sqrt=Sqrt('y')).get()
+    >>> vector.x_sqrt, vector.y_sqrt
+    (2.0, 3.46410)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Sqrt
+    >>> FloatField.register_lookup(Sqrt)
+    >>> # Get vectors whose sqrt() is less than 5
+    >>> vectors = Vector.objects.filter(x__sqrt__lt=5, y__sqrt__lt=5)
+
+``Tan``
+-------
+
+.. class:: Tan(expression, **extra)
+
+Returns the tangent of a numeric field or expression.
+
+Usage example::
+
+    >>> from django.db.models.functions import Tan
+    >>> Vector.objects.create(x=0, y=12)
+    >>> vector = Vector.objects.annotate(x_tan=Tan('x'), y_tan=Tan('y')).get()
+    >>> vector.x_tan, vector.y_tan
+    (0.0, -0.6358599286615808)
+
+It can also be registered as a transform. For example::
+
+    >>> from django.db.models import FloatField
+    >>> from django.db.models.functions import Tan
+    >>> FloatField.register_lookup(Tan)
+    >>> # Get vectors whose tangent is less than 0
+    >>> vectors = Vector.objects.filter(x__tan__lt=0, y__tan__lt=0)
+
 .. _text-functions:
 
 Text functions

docs/releases/2.2.txt

@@ -166,6 +166,8 @@ Models
 
 * Added support for PostgreSQL operator classes (:attr:`.Index.opclasses`).
 
+* Added many :ref:`math database functions <math-functions>`.
+
 Requests and Responses
 ~~~~~~~~~~~~~~~~~~~~~~
 

docs/spelling_wordlist

@@ -19,6 +19,7 @@ app
 appname
 apps
 architected
+arccosine
 arg
 args
 assistive

tests/db_functions/math/test_abs.py

@@ -0,0 +1,50 @@
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Abs
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class AbsTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-0.8'), n2=Decimal('1.2'))
+        obj = DecimalModel.objects.annotate(n1_abs=Abs('n1'), n2_abs=Abs('n2')).first()
+        self.assertIsInstance(obj.n1_abs, Decimal)
+        self.assertIsInstance(obj.n2_abs, Decimal)
+        self.assertEqual(obj.n1, -obj.n1_abs)
+        self.assertEqual(obj.n2, obj.n2_abs)
+
+    def test_float(self):
+        obj = FloatModel.objects.create(f1=-0.5, f2=12)
+        obj = FloatModel.objects.annotate(f1_abs=Abs('f1'), f2_abs=Abs('f2')).first()
+        self.assertIsInstance(obj.f1_abs, float)
+        self.assertIsInstance(obj.f2_abs, float)
+        self.assertEqual(obj.f1, -obj.f1_abs)
+        self.assertEqual(obj.f2, obj.f2_abs)
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=12, normal=0, big=-45)
+        obj = IntegerModel.objects.annotate(
+            small_abs=Abs('small'),
+            normal_abs=Abs('normal'),
+            big_abs=Abs('big'),
+        ).first()
+        self.assertIsInstance(obj.small_abs, int)
+        self.assertIsInstance(obj.normal_abs, int)
+        self.assertIsInstance(obj.big_abs, int)
+        self.assertEqual(obj.small, obj.small_abs)
+        self.assertEqual(obj.normal, obj.normal_abs)
+        self.assertEqual(obj.big, -obj.big_abs)
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Abs)
+            DecimalModel.objects.create(n1=Decimal('-1.5'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-0.5'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__abs__gt=1)
+            self.assertQuerysetEqual(objs, [Decimal('-1.5')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Abs)

tests/db_functions/math/test_acos.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import ACos
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class ACosTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-0.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_acos=ACos('n1'), n2_acos=ACos('n2')).first()
+        self.assertIsInstance(obj.n1_acos, Decimal)
+        self.assertIsInstance(obj.n2_acos, Decimal)
+        self.assertAlmostEqual(obj.n1_acos, Decimal(math.acos(obj.n1)))
+        self.assertAlmostEqual(obj.n2_acos, Decimal(math.acos(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-0.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_acos=ACos('f1'), f2_acos=ACos('f2')).first()
+        self.assertIsInstance(obj.f1_acos, float)
+        self.assertIsInstance(obj.f2_acos, float)
+        self.assertAlmostEqual(obj.f1_acos, math.acos(obj.f1))
+        self.assertAlmostEqual(obj.f2_acos, math.acos(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=0, normal=1, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_acos=ACos('small'),
+            normal_acos=ACos('normal'),
+            big_acos=ACos('big'),
+        ).first()
+        self.assertIsInstance(obj.small_acos, float)
+        self.assertIsInstance(obj.normal_acos, float)
+        self.assertIsInstance(obj.big_acos, float)
+        self.assertAlmostEqual(obj.small_acos, math.acos(obj.small))
+        self.assertAlmostEqual(obj.normal_acos, math.acos(obj.normal))
+        self.assertAlmostEqual(obj.big_acos, math.acos(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(ACos)
+            DecimalModel.objects.create(n1=Decimal('0.5'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-0.9'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__acos__lt=2)
+            self.assertQuerysetEqual(objs, [Decimal('0.5')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(ACos)

tests/db_functions/math/test_asin.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import ASin
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class ASinTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('0.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_asin=ASin('n1'), n2_asin=ASin('n2')).first()
+        self.assertIsInstance(obj.n1_asin, Decimal)
+        self.assertIsInstance(obj.n2_asin, Decimal)
+        self.assertAlmostEqual(obj.n1_asin, Decimal(math.asin(obj.n1)))
+        self.assertAlmostEqual(obj.n2_asin, Decimal(math.asin(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-0.5, f2=0.87)
+        obj = FloatModel.objects.annotate(f1_asin=ASin('f1'), f2_asin=ASin('f2')).first()
+        self.assertIsInstance(obj.f1_asin, float)
+        self.assertIsInstance(obj.f2_asin, float)
+        self.assertAlmostEqual(obj.f1_asin, math.asin(obj.f1))
+        self.assertAlmostEqual(obj.f2_asin, math.asin(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=0, normal=1, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_asin=ASin('small'),
+            normal_asin=ASin('normal'),
+            big_asin=ASin('big'),
+        ).first()
+        self.assertIsInstance(obj.small_asin, float)
+        self.assertIsInstance(obj.normal_asin, float)
+        self.assertIsInstance(obj.big_asin, float)
+        self.assertAlmostEqual(obj.small_asin, math.asin(obj.small))
+        self.assertAlmostEqual(obj.normal_asin, math.asin(obj.normal))
+        self.assertAlmostEqual(obj.big_asin, math.asin(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(ASin)
+            DecimalModel.objects.create(n1=Decimal('0.1'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__asin__gt=1)
+            self.assertQuerysetEqual(objs, [Decimal('1.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(ASin)

tests/db_functions/math/test_atan.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import ATan
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class ATanTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_atan=ATan('n1'), n2_atan=ATan('n2')).first()
+        self.assertIsInstance(obj.n1_atan, Decimal)
+        self.assertIsInstance(obj.n2_atan, Decimal)
+        self.assertAlmostEqual(obj.n1_atan, Decimal(math.atan(obj.n1)))
+        self.assertAlmostEqual(obj.n2_atan, Decimal(math.atan(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_atan=ATan('f1'), f2_atan=ATan('f2')).first()
+        self.assertIsInstance(obj.f1_atan, float)
+        self.assertIsInstance(obj.f2_atan, float)
+        self.assertAlmostEqual(obj.f1_atan, math.atan(obj.f1))
+        self.assertAlmostEqual(obj.f2_atan, math.atan(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_atan=ATan('small'),
+            normal_atan=ATan('normal'),
+            big_atan=ATan('big'),
+        ).first()
+        self.assertIsInstance(obj.small_atan, float)
+        self.assertIsInstance(obj.normal_atan, float)
+        self.assertIsInstance(obj.big_atan, float)
+        self.assertAlmostEqual(obj.small_atan, math.atan(obj.small))
+        self.assertAlmostEqual(obj.normal_atan, math.atan(obj.normal))
+        self.assertAlmostEqual(obj.big_atan, math.atan(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(ATan)
+            DecimalModel.objects.create(n1=Decimal('3.12'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-5'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__atan__gt=0)
+            self.assertQuerysetEqual(objs, [Decimal('3.12')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(ATan)

tests/db_functions/math/test_atan2.py

@@ -0,0 +1,33 @@
+import math
+from decimal import Decimal
+
+from django.db.models.functions import ATan2
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class ATan2Tests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-9.9'), n2=Decimal('4.6'))
+        obj = DecimalModel.objects.annotate(n_atan2=ATan2('n1', 'n2')).first()
+        self.assertIsInstance(obj.n_atan2, Decimal)
+        self.assertAlmostEqual(obj.n_atan2, Decimal(math.atan2(obj.n1, obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-25, f2=0.33)
+        obj = FloatModel.objects.annotate(f_atan2=ATan2('f1', 'f2')).first()
+        self.assertIsInstance(obj.f_atan2, float)
+        self.assertAlmostEqual(obj.f_atan2, math.atan2(obj.f1, obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=0, normal=1, big=10)
+        obj = IntegerModel.objects.annotate(
+            atan2_sn=ATan2('small', 'normal'),
+            atan2_nb=ATan2('normal', 'big'),
+        ).first()
+        self.assertIsInstance(obj.atan2_sn, float)
+        self.assertIsInstance(obj.atan2_nb, float)
+        self.assertAlmostEqual(obj.atan2_sn, math.atan2(obj.small, obj.normal))
+        self.assertAlmostEqual(obj.atan2_nb, math.atan2(obj.normal, obj.big))

tests/db_functions/math/test_ceil.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Ceil
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class CeilTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_ceil=Ceil('n1'), n2_ceil=Ceil('n2')).first()
+        self.assertIsInstance(obj.n1_ceil, Decimal)
+        self.assertIsInstance(obj.n2_ceil, Decimal)
+        self.assertEqual(obj.n1_ceil, Decimal(math.ceil(obj.n1)))
+        self.assertEqual(obj.n2_ceil, Decimal(math.ceil(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-12.5, f2=21.33)
+        obj = FloatModel.objects.annotate(f1_ceil=Ceil('f1'), f2_ceil=Ceil('f2')).first()
+        self.assertIsInstance(obj.f1_ceil, float)
+        self.assertIsInstance(obj.f2_ceil, float)
+        self.assertEqual(obj.f1_ceil, math.ceil(obj.f1))
+        self.assertEqual(obj.f2_ceil, math.ceil(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-11, normal=0, big=-100)
+        obj = IntegerModel.objects.annotate(
+            small_ceil=Ceil('small'),
+            normal_ceil=Ceil('normal'),
+            big_ceil=Ceil('big'),
+        ).first()
+        self.assertIsInstance(obj.small_ceil, int)
+        self.assertIsInstance(obj.normal_ceil, int)
+        self.assertIsInstance(obj.big_ceil, int)
+        self.assertEqual(obj.small_ceil, math.ceil(obj.small))
+        self.assertEqual(obj.normal_ceil, math.ceil(obj.normal))
+        self.assertEqual(obj.big_ceil, math.ceil(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Ceil)
+            DecimalModel.objects.create(n1=Decimal('3.12'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('1.25'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__ceil__gt=3)
+            self.assertQuerysetEqual(objs, [Decimal('3.12')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Ceil)

tests/db_functions/math/test_cos.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Cos
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class CosTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_cos=Cos('n1'), n2_cos=Cos('n2')).first()
+        self.assertIsInstance(obj.n1_cos, Decimal)
+        self.assertIsInstance(obj.n2_cos, Decimal)
+        self.assertAlmostEqual(obj.n1_cos, Decimal(math.cos(obj.n1)))
+        self.assertAlmostEqual(obj.n2_cos, Decimal(math.cos(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_cos=Cos('f1'), f2_cos=Cos('f2')).first()
+        self.assertIsInstance(obj.f1_cos, float)
+        self.assertIsInstance(obj.f2_cos, float)
+        self.assertAlmostEqual(obj.f1_cos, math.cos(obj.f1))
+        self.assertAlmostEqual(obj.f2_cos, math.cos(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_cos=Cos('small'),
+            normal_cos=Cos('normal'),
+            big_cos=Cos('big'),
+        ).first()
+        self.assertIsInstance(obj.small_cos, float)
+        self.assertIsInstance(obj.normal_cos, float)
+        self.assertIsInstance(obj.big_cos, float)
+        self.assertAlmostEqual(obj.small_cos, math.cos(obj.small))
+        self.assertAlmostEqual(obj.normal_cos, math.cos(obj.normal))
+        self.assertAlmostEqual(obj.big_cos, math.cos(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Cos)
+            DecimalModel.objects.create(n1=Decimal('-8.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('3.14'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__cos__gt=-0.2)
+            self.assertQuerysetEqual(objs, [Decimal('-8.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Cos)

tests/db_functions/math/test_cot.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Cot
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class CotTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_cot=Cot('n1'), n2_cot=Cot('n2')).first()
+        self.assertIsInstance(obj.n1_cot, Decimal)
+        self.assertIsInstance(obj.n2_cot, Decimal)
+        self.assertAlmostEqual(obj.n1_cot, Decimal(1 / math.tan(obj.n1)))
+        self.assertAlmostEqual(obj.n2_cot, Decimal(1 / math.tan(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_cot=Cot('f1'), f2_cot=Cot('f2')).first()
+        self.assertIsInstance(obj.f1_cot, float)
+        self.assertIsInstance(obj.f2_cot, float)
+        self.assertAlmostEqual(obj.f1_cot, 1 / math.tan(obj.f1))
+        self.assertAlmostEqual(obj.f2_cot, 1 / math.tan(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-5, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_cot=Cot('small'),
+            normal_cot=Cot('normal'),
+            big_cot=Cot('big'),
+        ).first()
+        self.assertIsInstance(obj.small_cot, float)
+        self.assertIsInstance(obj.normal_cot, float)
+        self.assertIsInstance(obj.big_cot, float)
+        self.assertAlmostEqual(obj.small_cot, 1 / math.tan(obj.small))
+        self.assertAlmostEqual(obj.normal_cot, 1 / math.tan(obj.normal))
+        self.assertAlmostEqual(obj.big_cot, 1 / math.tan(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Cot)
+            DecimalModel.objects.create(n1=Decimal('12.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__cot__gt=0)
+            self.assertQuerysetEqual(objs, [Decimal('1.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Cot)

tests/db_functions/math/test_degrees.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Degrees
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class DegreesTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_degrees=Degrees('n1'), n2_degrees=Degrees('n2')).first()
+        self.assertIsInstance(obj.n1_degrees, Decimal)
+        self.assertIsInstance(obj.n2_degrees, Decimal)
+        self.assertAlmostEqual(obj.n1_degrees, Decimal(math.degrees(obj.n1)))
+        self.assertAlmostEqual(obj.n2_degrees, Decimal(math.degrees(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_degrees=Degrees('f1'), f2_degrees=Degrees('f2')).first()
+        self.assertIsInstance(obj.f1_degrees, float)
+        self.assertIsInstance(obj.f2_degrees, float)
+        self.assertAlmostEqual(obj.f1_degrees, math.degrees(obj.f1))
+        self.assertAlmostEqual(obj.f2_degrees, math.degrees(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_degrees=Degrees('small'),
+            normal_degrees=Degrees('normal'),
+            big_degrees=Degrees('big'),
+        ).first()
+        self.assertIsInstance(obj.small_degrees, float)
+        self.assertIsInstance(obj.normal_degrees, float)
+        self.assertIsInstance(obj.big_degrees, float)
+        self.assertAlmostEqual(obj.small_degrees, math.degrees(obj.small))
+        self.assertAlmostEqual(obj.normal_degrees, math.degrees(obj.normal))
+        self.assertAlmostEqual(obj.big_degrees, math.degrees(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Degrees)
+            DecimalModel.objects.create(n1=Decimal('5.4'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-30'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__degrees__gt=0)
+            self.assertQuerysetEqual(objs, [Decimal('5.4')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Degrees)

tests/db_functions/math/test_exp.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Exp
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class ExpTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_exp=Exp('n1'), n2_exp=Exp('n2')).first()
+        self.assertIsInstance(obj.n1_exp, Decimal)
+        self.assertIsInstance(obj.n2_exp, Decimal)
+        self.assertAlmostEqual(obj.n1_exp, Decimal(math.exp(obj.n1)))
+        self.assertAlmostEqual(obj.n2_exp, Decimal(math.exp(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_exp=Exp('f1'), f2_exp=Exp('f2')).first()
+        self.assertIsInstance(obj.f1_exp, float)
+        self.assertIsInstance(obj.f2_exp, float)
+        self.assertAlmostEqual(obj.f1_exp, math.exp(obj.f1))
+        self.assertAlmostEqual(obj.f2_exp, math.exp(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_exp=Exp('small'),
+            normal_exp=Exp('normal'),
+            big_exp=Exp('big'),
+        ).first()
+        self.assertIsInstance(obj.small_exp, float)
+        self.assertIsInstance(obj.normal_exp, float)
+        self.assertIsInstance(obj.big_exp, float)
+        self.assertAlmostEqual(obj.small_exp, math.exp(obj.small))
+        self.assertAlmostEqual(obj.normal_exp, math.exp(obj.normal))
+        self.assertAlmostEqual(obj.big_exp, math.exp(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Exp)
+            DecimalModel.objects.create(n1=Decimal('12.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__exp__gt=10)
+            self.assertQuerysetEqual(objs, [Decimal('12.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Exp)

tests/db_functions/math/test_floor.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Floor
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class FloorTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_floor=Floor('n1'), n2_floor=Floor('n2')).first()
+        self.assertIsInstance(obj.n1_floor, Decimal)
+        self.assertIsInstance(obj.n2_floor, Decimal)
+        self.assertEqual(obj.n1_floor, Decimal(math.floor(obj.n1)))
+        self.assertEqual(obj.n2_floor, Decimal(math.floor(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_floor=Floor('f1'), f2_floor=Floor('f2')).first()
+        self.assertIsInstance(obj.f1_floor, float)
+        self.assertIsInstance(obj.f2_floor, float)
+        self.assertEqual(obj.f1_floor, math.floor(obj.f1))
+        self.assertEqual(obj.f2_floor, math.floor(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_floor=Floor('small'),
+            normal_floor=Floor('normal'),
+            big_floor=Floor('big'),
+        ).first()
+        self.assertIsInstance(obj.small_floor, int)
+        self.assertIsInstance(obj.normal_floor, int)
+        self.assertIsInstance(obj.big_floor, int)
+        self.assertEqual(obj.small_floor, math.floor(obj.small))
+        self.assertEqual(obj.normal_floor, math.floor(obj.normal))
+        self.assertEqual(obj.big_floor, math.floor(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Floor)
+            DecimalModel.objects.create(n1=Decimal('5.4'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('3.4'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__floor__gt=4)
+            self.assertQuerysetEqual(objs, [Decimal('5.4')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Floor)

tests/db_functions/math/test_ln.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Ln
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class LnTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_ln=Ln('n1'), n2_ln=Ln('n2')).first()
+        self.assertIsInstance(obj.n1_ln, Decimal)
+        self.assertIsInstance(obj.n2_ln, Decimal)
+        self.assertAlmostEqual(obj.n1_ln, Decimal(math.log(obj.n1)))
+        self.assertAlmostEqual(obj.n2_ln, Decimal(math.log(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_ln=Ln('f1'), f2_ln=Ln('f2')).first()
+        self.assertIsInstance(obj.f1_ln, float)
+        self.assertIsInstance(obj.f2_ln, float)
+        self.assertAlmostEqual(obj.f1_ln, math.log(obj.f1))
+        self.assertAlmostEqual(obj.f2_ln, math.log(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=20, normal=15, big=1)
+        obj = IntegerModel.objects.annotate(
+            small_ln=Ln('small'),
+            normal_ln=Ln('normal'),
+            big_ln=Ln('big'),
+        ).first()
+        self.assertIsInstance(obj.small_ln, float)
+        self.assertIsInstance(obj.normal_ln, float)
+        self.assertIsInstance(obj.big_ln, float)
+        self.assertAlmostEqual(obj.small_ln, math.log(obj.small))
+        self.assertAlmostEqual(obj.normal_ln, math.log(obj.normal))
+        self.assertAlmostEqual(obj.big_ln, math.log(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Ln)
+            DecimalModel.objects.create(n1=Decimal('12.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__ln__gt=0)
+            self.assertQuerysetEqual(objs, [Decimal('12.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Ln)

tests/db_functions/math/test_log.py

@@ -0,0 +1,36 @@
+import math
+from decimal import Decimal
+
+from django.db.models.functions import Log
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class LogTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('12.9'), n2=Decimal('3.6'))
+        obj = DecimalModel.objects.annotate(n_log=Log('n1', 'n2')).first()
+        self.assertIsInstance(obj.n_log, Decimal)
+        self.assertAlmostEqual(obj.n_log, Decimal(math.log(obj.n2, obj.n1)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=2.0, f2=4.0)
+        obj = FloatModel.objects.annotate(f_log=Log('f1', 'f2')).first()
+        self.assertIsInstance(obj.f_log, float)
+        self.assertAlmostEqual(obj.f_log, math.log(obj.f2, obj.f1))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=4, normal=8, big=2)
+        obj = IntegerModel.objects.annotate(
+            small_log=Log('small', 'big'),
+            normal_log=Log('normal', 'big'),
+            big_log=Log('big', 'big'),
+        ).first()
+        self.assertIsInstance(obj.small_log, float)
+        self.assertIsInstance(obj.normal_log, float)
+        self.assertIsInstance(obj.big_log, float)
+        self.assertAlmostEqual(obj.small_log, math.log(obj.big, obj.small))
+        self.assertAlmostEqual(obj.normal_log, math.log(obj.big, obj.normal))
+        self.assertAlmostEqual(obj.big_log, math.log(obj.big, obj.big))

tests/db_functions/math/test_mod.py

@@ -0,0 +1,36 @@
+import math
+from decimal import Decimal
+
+from django.db.models.functions import Mod
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class ModTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-9.9'), n2=Decimal('4.6'))
+        obj = DecimalModel.objects.annotate(n_mod=Mod('n1', 'n2')).first()
+        self.assertIsInstance(obj.n_mod, Decimal)
+        self.assertAlmostEqual(obj.n_mod, Decimal(math.fmod(obj.n1, obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-25, f2=0.33)
+        obj = FloatModel.objects.annotate(f_mod=Mod('f1', 'f2')).first()
+        self.assertIsInstance(obj.f_mod, float)
+        self.assertAlmostEqual(obj.f_mod, math.fmod(obj.f1, obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=20, normal=15, big=1)
+        obj = IntegerModel.objects.annotate(
+            small_mod=Mod('small', 'normal'),
+            normal_mod=Mod('normal', 'big'),
+            big_mod=Mod('big', 'small'),
+        ).first()
+        self.assertIsInstance(obj.small_mod, float)
+        self.assertIsInstance(obj.normal_mod, float)
+        self.assertIsInstance(obj.big_mod, float)
+        self.assertEqual(obj.small_mod, math.fmod(obj.small, obj.normal))
+        self.assertEqual(obj.normal_mod, math.fmod(obj.normal, obj.big))
+        self.assertEqual(obj.big_mod, math.fmod(obj.big, obj.small))

tests/db_functions/math/test_pi.py

@@ -0,0 +1,15 @@
+import math
+
+from django.db.models.functions import Pi
+from django.test import TestCase
+
+from ..models import FloatModel
+
+
+class PiTests(TestCase):
+
+    def test(self):
+        FloatModel.objects.create(f1=2.5, f2=15.9)
+        obj = FloatModel.objects.annotate(pi=Pi()).first()
+        self.assertIsInstance(obj.pi, float)
+        self.assertAlmostEqual(obj.pi, math.pi, places=5)

tests/db_functions/math/test_power.py

@@ -0,0 +1,35 @@
+from decimal import Decimal
+
+from django.db.models.functions import Power
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class PowerTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('1.0'), n2=Decimal('-0.6'))
+        obj = DecimalModel.objects.annotate(n_power=Power('n1', 'n2')).first()
+        self.assertIsInstance(obj.n_power, Decimal)
+        self.assertAlmostEqual(obj.n_power, Decimal(obj.n1 ** obj.n2))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=2.3, f2=1.1)
+        obj = FloatModel.objects.annotate(f_power=Power('f1', 'f2')).first()
+        self.assertIsInstance(obj.f_power, float)
+        self.assertAlmostEqual(obj.f_power, obj.f1 ** obj.f2)
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-1, normal=20, big=3)
+        obj = IntegerModel.objects.annotate(
+            small_power=Power('small', 'normal'),
+            normal_power=Power('normal', 'big'),
+            big_power=Power('big', 'small'),
+        ).first()
+        self.assertIsInstance(obj.small_power, float)
+        self.assertIsInstance(obj.normal_power, float)
+        self.assertIsInstance(obj.big_power, float)
+        self.assertAlmostEqual(obj.small_power, obj.small ** obj.normal)
+        self.assertAlmostEqual(obj.normal_power, obj.normal ** obj.big)
+        self.assertAlmostEqual(obj.big_power, obj.big ** obj.small)

tests/db_functions/math/test_radians.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Radians
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class RadiansTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_radians=Radians('n1'), n2_radians=Radians('n2')).first()
+        self.assertIsInstance(obj.n1_radians, Decimal)
+        self.assertIsInstance(obj.n2_radians, Decimal)
+        self.assertAlmostEqual(obj.n1_radians, Decimal(math.radians(obj.n1)))
+        self.assertAlmostEqual(obj.n2_radians, Decimal(math.radians(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_radians=Radians('f1'), f2_radians=Radians('f2')).first()
+        self.assertIsInstance(obj.f1_radians, float)
+        self.assertIsInstance(obj.f2_radians, float)
+        self.assertAlmostEqual(obj.f1_radians, math.radians(obj.f1))
+        self.assertAlmostEqual(obj.f2_radians, math.radians(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_radians=Radians('small'),
+            normal_radians=Radians('normal'),
+            big_radians=Radians('big'),
+        ).first()
+        self.assertIsInstance(obj.small_radians, float)
+        self.assertIsInstance(obj.normal_radians, float)
+        self.assertIsInstance(obj.big_radians, float)
+        self.assertAlmostEqual(obj.small_radians, math.radians(obj.small))
+        self.assertAlmostEqual(obj.normal_radians, math.radians(obj.normal))
+        self.assertAlmostEqual(obj.big_radians, math.radians(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Radians)
+            DecimalModel.objects.create(n1=Decimal('2.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__radians__gt=0)
+            self.assertQuerysetEqual(objs, [Decimal('2.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Radians)

tests/db_functions/math/test_round.py

@@ -0,0 +1,50 @@
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Round
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class RoundTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_round=Round('n1'), n2_round=Round('n2')).first()
+        self.assertIsInstance(obj.n1_round, Decimal)
+        self.assertIsInstance(obj.n2_round, Decimal)
+        self.assertAlmostEqual(obj.n1_round, round(obj.n1))
+        self.assertAlmostEqual(obj.n2_round, round(obj.n2))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.55, f2=0.55)
+        obj = FloatModel.objects.annotate(f1_round=Round('f1'), f2_round=Round('f2')).first()
+        self.assertIsInstance(obj.f1_round, float)
+        self.assertIsInstance(obj.f2_round, float)
+        self.assertAlmostEqual(obj.f1_round, round(obj.f1))
+        self.assertAlmostEqual(obj.f2_round, round(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_round=Round('small'),
+            normal_round=Round('normal'),
+            big_round=Round('big'),
+        ).first()
+        self.assertIsInstance(obj.small_round, int)
+        self.assertIsInstance(obj.normal_round, int)
+        self.assertIsInstance(obj.big_round, int)
+        self.assertEqual(obj.small_round, round(obj.small))
+        self.assertEqual(obj.normal_round, round(obj.normal))
+        self.assertEqual(obj.big_round, round(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Round)
+            DecimalModel.objects.create(n1=Decimal('2.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('-1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__round__gt=0)
+            self.assertQuerysetEqual(objs, [Decimal('2.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Round)

tests/db_functions/math/test_sin.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Sin
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class SinTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_sin=Sin('n1'), n2_sin=Sin('n2')).first()
+        self.assertIsInstance(obj.n1_sin, Decimal)
+        self.assertIsInstance(obj.n2_sin, Decimal)
+        self.assertAlmostEqual(obj.n1_sin, Decimal(math.sin(obj.n1)))
+        self.assertAlmostEqual(obj.n2_sin, Decimal(math.sin(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_sin=Sin('f1'), f2_sin=Sin('f2')).first()
+        self.assertIsInstance(obj.f1_sin, float)
+        self.assertIsInstance(obj.f2_sin, float)
+        self.assertAlmostEqual(obj.f1_sin, math.sin(obj.f1))
+        self.assertAlmostEqual(obj.f2_sin, math.sin(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_sin=Sin('small'),
+            normal_sin=Sin('normal'),
+            big_sin=Sin('big'),
+        ).first()
+        self.assertIsInstance(obj.small_sin, float)
+        self.assertIsInstance(obj.normal_sin, float)
+        self.assertIsInstance(obj.big_sin, float)
+        self.assertAlmostEqual(obj.small_sin, math.sin(obj.small))
+        self.assertAlmostEqual(obj.normal_sin, math.sin(obj.normal))
+        self.assertAlmostEqual(obj.big_sin, math.sin(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Sin)
+            DecimalModel.objects.create(n1=Decimal('5.4'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('0.1'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__sin__lt=0)
+            self.assertQuerysetEqual(objs, [Decimal('5.4')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Sin)

tests/db_functions/math/test_sqrt.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Sqrt
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class SqrtTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_sqrt=Sqrt('n1'), n2_sqrt=Sqrt('n2')).first()
+        self.assertIsInstance(obj.n1_sqrt, Decimal)
+        self.assertIsInstance(obj.n2_sqrt, Decimal)
+        self.assertAlmostEqual(obj.n1_sqrt, Decimal(math.sqrt(obj.n1)))
+        self.assertAlmostEqual(obj.n2_sqrt, Decimal(math.sqrt(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_sqrt=Sqrt('f1'), f2_sqrt=Sqrt('f2')).first()
+        self.assertIsInstance(obj.f1_sqrt, float)
+        self.assertIsInstance(obj.f2_sqrt, float)
+        self.assertAlmostEqual(obj.f1_sqrt, math.sqrt(obj.f1))
+        self.assertAlmostEqual(obj.f2_sqrt, math.sqrt(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=20, normal=15, big=1)
+        obj = IntegerModel.objects.annotate(
+            small_sqrt=Sqrt('small'),
+            normal_sqrt=Sqrt('normal'),
+            big_sqrt=Sqrt('big'),
+        ).first()
+        self.assertIsInstance(obj.small_sqrt, float)
+        self.assertIsInstance(obj.normal_sqrt, float)
+        self.assertIsInstance(obj.big_sqrt, float)
+        self.assertAlmostEqual(obj.small_sqrt, math.sqrt(obj.small))
+        self.assertAlmostEqual(obj.normal_sqrt, math.sqrt(obj.normal))
+        self.assertAlmostEqual(obj.big_sqrt, math.sqrt(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Sqrt)
+            DecimalModel.objects.create(n1=Decimal('6.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('1.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__sqrt__gt=2)
+            self.assertQuerysetEqual(objs, [Decimal('6.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Sqrt)

tests/db_functions/math/test_tan.py

@@ -0,0 +1,51 @@
+import math
+from decimal import Decimal
+
+from django.db.models import DecimalField
+from django.db.models.functions import Tan
+from django.test import TestCase
+
+from ..models import DecimalModel, FloatModel, IntegerModel
+
+
+class TanTests(TestCase):
+
+    def test_decimal(self):
+        DecimalModel.objects.create(n1=Decimal('-12.9'), n2=Decimal('0.6'))
+        obj = DecimalModel.objects.annotate(n1_tan=Tan('n1'), n2_tan=Tan('n2')).first()
+        self.assertIsInstance(obj.n1_tan, Decimal)
+        self.assertIsInstance(obj.n2_tan, Decimal)
+        self.assertAlmostEqual(obj.n1_tan, Decimal(math.tan(obj.n1)))
+        self.assertAlmostEqual(obj.n2_tan, Decimal(math.tan(obj.n2)))
+
+    def test_float(self):
+        FloatModel.objects.create(f1=-27.5, f2=0.33)
+        obj = FloatModel.objects.annotate(f1_tan=Tan('f1'), f2_tan=Tan('f2')).first()
+        self.assertIsInstance(obj.f1_tan, float)
+        self.assertIsInstance(obj.f2_tan, float)
+        self.assertAlmostEqual(obj.f1_tan, math.tan(obj.f1))
+        self.assertAlmostEqual(obj.f2_tan, math.tan(obj.f2))
+
+    def test_integer(self):
+        IntegerModel.objects.create(small=-20, normal=15, big=-1)
+        obj = IntegerModel.objects.annotate(
+            small_tan=Tan('small'),
+            normal_tan=Tan('normal'),
+            big_tan=Tan('big'),
+        ).first()
+        self.assertIsInstance(obj.small_tan, float)
+        self.assertIsInstance(obj.normal_tan, float)
+        self.assertIsInstance(obj.big_tan, float)
+        self.assertAlmostEqual(obj.small_tan, math.tan(obj.small))
+        self.assertAlmostEqual(obj.normal_tan, math.tan(obj.normal))
+        self.assertAlmostEqual(obj.big_tan, math.tan(obj.big))
+
+    def test_transform(self):
+        try:
+            DecimalField.register_lookup(Tan)
+            DecimalModel.objects.create(n1=Decimal('0.0'), n2=Decimal('0'))
+            DecimalModel.objects.create(n1=Decimal('12.0'), n2=Decimal('0'))
+            objs = DecimalModel.objects.filter(n1__tan__lt=0)
+            self.assertQuerysetEqual(objs, [Decimal('12.0')], lambda a: a.n1)
+        finally:
+            DecimalField._unregister_lookup(Tan)

tests/db_functions/models.py

@@ -54,3 +54,14 @@ class DTModel(models.Model):
 class DecimalModel(models.Model):
     n1 = models.DecimalField(decimal_places=2, max_digits=6)
     n2 = models.DecimalField(decimal_places=2, max_digits=6)
+
+
+class IntegerModel(models.Model):
+    big = models.BigIntegerField(null=True, blank=True)
+    normal = models.IntegerField(null=True, blank=True)
+    small = models.SmallIntegerField(null=True, blank=True)
+
+
+class FloatModel(models.Model):
+    f1 = models.FloatField(null=True, blank=True)
+    f2 = models.FloatField(null=True, blank=True)