mixins.py 2.3 KB

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  1. import sys
  2. from django.db.models.fields import DecimalField, FloatField, IntegerField
  3. from django.db.models.functions import Cast
  4. class FixDecimalInputMixin:
  5. def as_postgresql(self, compiler, connection, **extra_context):
  6. # Cast FloatField to DecimalField as PostgreSQL doesn't support the
  7. # following function signatures:
  8. # - LOG(double, double)
  9. # - MOD(double, double)
  10. output_field = DecimalField(decimal_places=sys.float_info.dig, max_digits=1000)
  11. clone = self.copy()
  12. clone.set_source_expressions(
  13. [
  14. (
  15. Cast(expression, output_field)
  16. if isinstance(expression.output_field, FloatField)
  17. else expression
  18. )
  19. for expression in self.get_source_expressions()
  20. ]
  21. )
  22. return clone.as_sql(compiler, connection, **extra_context)
  23. class FixDurationInputMixin:
  24. def as_mysql(self, compiler, connection, **extra_context):
  25. sql, params = super().as_sql(compiler, connection, **extra_context)
  26. if self.output_field.get_internal_type() == "DurationField":
  27. sql = "CAST(%s AS SIGNED)" % sql
  28. return sql, params
  29. def as_oracle(self, compiler, connection, **extra_context):
  30. if (
  31. self.output_field.get_internal_type() == "DurationField"
  32. and not connection.features.supports_aggregation_over_interval_types
  33. ):
  34. expression = self.get_source_expressions()[0]
  35. options = self._get_repr_options()
  36. from django.db.backends.oracle.functions import (
  37. IntervalToSeconds,
  38. SecondsToInterval,
  39. )
  40. return compiler.compile(
  41. SecondsToInterval(
  42. self.__class__(IntervalToSeconds(expression), **options)
  43. )
  44. )
  45. return super().as_sql(compiler, connection, **extra_context)
  46. class NumericOutputFieldMixin:
  47. def _resolve_output_field(self):
  48. source_fields = self.get_source_fields()
  49. if any(isinstance(s, DecimalField) for s in source_fields):
  50. return DecimalField()
  51. if any(isinstance(s, IntegerField) for s in source_fields):
  52. return FloatField()
  53. return super()._resolve_output_field() if source_fields else FloatField()