Source code for django.db.models.functions.math
import math
from django.db.models.expressions import Func, Value
from django.db.models.fields import FloatField, IntegerField
from django.db.models.functions import Cast
from django.db.models.functions.mixins import (
FixDecimalInputMixin,
NumericOutputFieldMixin,
)
from django.db.models.lookups import Transform
[docs]class ATan2(NumericOutputFieldMixin, Func):
function = "ATAN2"
arity = 2
def as_sqlite(self, compiler, connection, **extra_context):
if not getattr(
connection.ops, "spatialite", False
) or connection.ops.spatial_version >= (5, 0, 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 < 5.0.0.
# 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, **extra_context)
[docs]class Ceil(Transform):
function = "CEILING"
lookup_name = "ceil"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="CEIL", **extra_context)
[docs]class Cot(NumericOutputFieldMixin, Transform):
function = "COT"
lookup_name = "cot"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, template="(1 / TAN(%(expressions)s))", **extra_context
)
[docs]class Degrees(NumericOutputFieldMixin, Transform):
function = "DEGREES"
lookup_name = "degrees"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="((%%(expressions)s) * 180 / %s)" % math.pi,
**extra_context,
)
[docs]class Log(FixDecimalInputMixin, NumericOutputFieldMixin, Func):
function = "LOG"
arity = 2
def as_sqlite(self, compiler, connection, **extra_context):
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, **extra_context)
[docs]class Pi(NumericOutputFieldMixin, Func):
function = "PI"
arity = 0
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, template=str(math.pi), **extra_context
)
[docs]class Radians(NumericOutputFieldMixin, Transform):
function = "RADIANS"
lookup_name = "radians"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="((%%(expressions)s) * %s / 180)" % math.pi,
**extra_context,
)
[docs]class Random(NumericOutputFieldMixin, Func):
function = "RANDOM"
arity = 0
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="RAND", **extra_context)
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, function="DBMS_RANDOM.VALUE", **extra_context
)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="RAND", **extra_context)
def get_group_by_cols(self):
return []
[docs]class Round(FixDecimalInputMixin, Transform):
function = "ROUND"
lookup_name = "round"
arity = None # Override Transform's arity=1 to enable passing precision.
def __init__(self, expression, precision=0, **extra):
super().__init__(expression, precision, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
precision = self.get_source_expressions()[1]
if isinstance(precision, Value) and precision.value < 0:
raise ValueError("SQLite does not support negative precision.")
return super().as_sqlite(compiler, connection, **extra_context)
def _resolve_output_field(self):
source = self.get_source_expressions()[0]
return source.output_field