Исходный код django.contrib.postgres.fields.ranges

import datetime
import json

from psycopg2.extras import DateRange, DateTimeTZRange, NumericRange, Range

from django.contrib.postgres import forms, lookups
from django.db import models
from django.db.models.lookups import PostgresOperatorLookup

from .utils import AttributeSetter

__all__ = [
    'RangeField', 'IntegerRangeField', 'BigIntegerRangeField',
    'DecimalRangeField', 'DateTimeRangeField', 'DateRangeField',
    'RangeBoundary', 'RangeOperators',
]


[документация]class RangeBoundary(models.Expression): """A class that represents range boundaries.""" def __init__(self, inclusive_lower=True, inclusive_upper=False): self.lower = '[' if inclusive_lower else '(' self.upper = ']' if inclusive_upper else ')' def as_sql(self, compiler, connection): return "'%s%s'" % (self.lower, self.upper), []
[документация]class RangeOperators: # https://www.postgresql.org/docs/current/functions-range.html#RANGE-OPERATORS-TABLE EQUAL = '=' NOT_EQUAL = '<>' CONTAINS = '@>' CONTAINED_BY = '<@' OVERLAPS = '&&' FULLY_LT = '<<' FULLY_GT = '>>' NOT_LT = '&>' NOT_GT = '&<' ADJACENT_TO = '-|-'
[документация]class RangeField(models.Field): empty_strings_allowed = False def __init__(self, *args, **kwargs): # Initializing base_field here ensures that its model matches the model for self. if hasattr(self, 'base_field'): self.base_field = self.base_field() super().__init__(*args, **kwargs) @property def model(self): try: return self.__dict__['model'] except KeyError: raise AttributeError("'%s' object has no attribute 'model'" % self.__class__.__name__) @model.setter def model(self, model): self.__dict__['model'] = model self.base_field.model = model @classmethod def _choices_is_value(cls, value): return isinstance(value, (list, tuple)) or super()._choices_is_value(value) def get_prep_value(self, value): if value is None: return None elif isinstance(value, Range): return value elif isinstance(value, (list, tuple)): return self.range_type(value[0], value[1]) return value def to_python(self, value): if isinstance(value, str): # Assume we're deserializing vals = json.loads(value) for end in ('lower', 'upper'): if end in vals: vals[end] = self.base_field.to_python(vals[end]) value = self.range_type(**vals) elif isinstance(value, (list, tuple)): value = self.range_type(value[0], value[1]) return value def set_attributes_from_name(self, name): super().set_attributes_from_name(name) self.base_field.set_attributes_from_name(name) def value_to_string(self, obj): value = self.value_from_object(obj) if value is None: return None if value.isempty: return json.dumps({"empty": True}) base_field = self.base_field result = {"bounds": value._bounds} for end in ('lower', 'upper'): val = getattr(value, end) if val is None: result[end] = None else: obj = AttributeSetter(base_field.attname, val) result[end] = base_field.value_to_string(obj) return json.dumps(result) def formfield(self, **kwargs): kwargs.setdefault('form_class', self.form_field) return super().formfield(**kwargs)
[документация]class IntegerRangeField(RangeField): base_field = models.IntegerField range_type = NumericRange form_field = forms.IntegerRangeField def db_type(self, connection): return 'int4range'
[документация]class BigIntegerRangeField(RangeField): base_field = models.BigIntegerField range_type = NumericRange form_field = forms.IntegerRangeField def db_type(self, connection): return 'int8range'
[документация]class DecimalRangeField(RangeField): base_field = models.DecimalField range_type = NumericRange form_field = forms.DecimalRangeField def db_type(self, connection): return 'numrange'
[документация]class DateTimeRangeField(RangeField): base_field = models.DateTimeField range_type = DateTimeTZRange form_field = forms.DateTimeRangeField def db_type(self, connection): return 'tstzrange'
[документация]class DateRangeField(RangeField): base_field = models.DateField range_type = DateRange form_field = forms.DateRangeField def db_type(self, connection): return 'daterange'
RangeField.register_lookup(lookups.DataContains) RangeField.register_lookup(lookups.ContainedBy) RangeField.register_lookup(lookups.Overlap) class DateTimeRangeContains(PostgresOperatorLookup): """ Lookup for Date/DateTimeRange containment to cast the rhs to the correct type. """ lookup_name = 'contains' postgres_operator = RangeOperators.CONTAINS def process_rhs(self, compiler, connection): # Transform rhs value for db lookup. if isinstance(self.rhs, datetime.date): value = models.Value(self.rhs) self.rhs = value.resolve_expression(compiler.query) return super().process_rhs(compiler, connection) def as_postgresql(self, compiler, connection): sql, params = super().as_postgresql(compiler, connection) # Cast the rhs if needed. cast_sql = '' if ( isinstance(self.rhs, models.Expression) and self.rhs._output_field_or_none and # Skip cast if rhs has a matching range type. not isinstance(self.rhs._output_field_or_none, self.lhs.output_field.__class__) ): cast_internal_type = self.lhs.output_field.base_field.get_internal_type() cast_sql = '::{}'.format(connection.data_types.get(cast_internal_type)) return '%s%s' % (sql, cast_sql), params DateRangeField.register_lookup(DateTimeRangeContains) DateTimeRangeField.register_lookup(DateTimeRangeContains) class RangeContainedBy(PostgresOperatorLookup): lookup_name = 'contained_by' type_mapping = { 'smallint': 'int4range', 'integer': 'int4range', 'bigint': 'int8range', 'double precision': 'numrange', 'numeric': 'numrange', 'date': 'daterange', 'timestamp with time zone': 'tstzrange', } postgres_operator = RangeOperators.CONTAINED_BY def process_rhs(self, compiler, connection): rhs, rhs_params = super().process_rhs(compiler, connection) # Ignore precision for DecimalFields. db_type = self.lhs.output_field.cast_db_type(connection).split('(')[0] cast_type = self.type_mapping[db_type] return '%s::%s' % (rhs, cast_type), rhs_params def process_lhs(self, compiler, connection): lhs, lhs_params = super().process_lhs(compiler, connection) if isinstance(self.lhs.output_field, models.FloatField): lhs = '%s::numeric' % lhs elif isinstance(self.lhs.output_field, models.SmallIntegerField): lhs = '%s::integer' % lhs return lhs, lhs_params def get_prep_lookup(self): return RangeField().get_prep_value(self.rhs) models.DateField.register_lookup(RangeContainedBy) models.DateTimeField.register_lookup(RangeContainedBy) models.IntegerField.register_lookup(RangeContainedBy) models.FloatField.register_lookup(RangeContainedBy) models.DecimalField.register_lookup(RangeContainedBy) @RangeField.register_lookup class FullyLessThan(PostgresOperatorLookup): lookup_name = 'fully_lt' postgres_operator = RangeOperators.FULLY_LT @RangeField.register_lookup class FullGreaterThan(PostgresOperatorLookup): lookup_name = 'fully_gt' postgres_operator = RangeOperators.FULLY_GT @RangeField.register_lookup class NotLessThan(PostgresOperatorLookup): lookup_name = 'not_lt' postgres_operator = RangeOperators.NOT_LT @RangeField.register_lookup class NotGreaterThan(PostgresOperatorLookup): lookup_name = 'not_gt' postgres_operator = RangeOperators.NOT_GT @RangeField.register_lookup class AdjacentToLookup(PostgresOperatorLookup): lookup_name = 'adjacent_to' postgres_operator = RangeOperators.ADJACENT_TO @RangeField.register_lookup class RangeStartsWith(models.Transform): lookup_name = 'startswith' function = 'lower' @property def output_field(self): return self.lhs.output_field.base_field @RangeField.register_lookup class RangeEndsWith(models.Transform): lookup_name = 'endswith' function = 'upper' @property def output_field(self): return self.lhs.output_field.base_field @RangeField.register_lookup class IsEmpty(models.Transform): lookup_name = 'isempty' function = 'isempty' output_field = models.BooleanField() @RangeField.register_lookup class LowerInclusive(models.Transform): lookup_name = 'lower_inc' function = 'LOWER_INC' output_field = models.BooleanField() @RangeField.register_lookup class LowerInfinite(models.Transform): lookup_name = 'lower_inf' function = 'LOWER_INF' output_field = models.BooleanField() @RangeField.register_lookup class UpperInclusive(models.Transform): lookup_name = 'upper_inc' function = 'UPPER_INC' output_field = models.BooleanField() @RangeField.register_lookup class UpperInfinite(models.Transform): lookup_name = 'upper_inf' function = 'UPPER_INF' output_field = models.BooleanField()
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