import sys
from django.db.models.fields import DecimalField, FloatField, IntegerField
from django.db.models.functions import Cast
class FixDecimalInputMixin:
def as_postgresql(self, compiler, connection, **extra_context):
# 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, **extra_context)
class FixDurationInputMixin:
def as_mysql(self, compiler, connection, **extra_context):
sql, params = super().as_sql(compiler, connection, **extra_context)
if self.output_field.get_internal_type() == 'DurationField':
sql = 'CAST(%s AS SIGNED)' % sql
return sql, params
def as_oracle(self, compiler, connection, **extra_context):
if self.output_field.get_internal_type() == 'DurationField':
expression = self.get_source_expressions()[0]
options = self._get_repr_options()
from django.db.backends.oracle.functions import IntervalToSeconds, SecondsToInterval
return compiler.compile(
SecondsToInterval(self.__class__(IntervalToSeconds(expression), **options))
)
return super().as_sql(compiler, connection, **extra_context)
class NumericOutputFieldMixin:
def _resolve_output_field(self):
source_fields = self.get_source_fields()
if any(isinstance(s, DecimalField) for s in source_fields):
return DecimalField()
if any(isinstance(s, IntegerField) for s in source_fields):
return FloatField()
return super()._resolve_output_field() if source_fields else FloatField()