Source code for 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 .utils import AttributeSetter
__all__ = [
'RangeField', 'IntegerRangeField', 'BigIntegerRangeField',
'DecimalRangeField', 'DateTimeRangeField', 'DateRangeField',
'FloatRangeField',
]
[docs]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
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)
[docs]class IntegerRangeField(RangeField):
base_field = models.IntegerField
range_type = NumericRange
form_field = forms.IntegerRangeField
def db_type(self, connection):
return 'int4range'
[docs]class BigIntegerRangeField(RangeField):
base_field = models.BigIntegerField
range_type = NumericRange
form_field = forms.IntegerRangeField
def db_type(self, connection):
return 'int8range'
[docs]class DecimalRangeField(RangeField):
base_field = models.DecimalField
range_type = NumericRange
form_field = forms.DecimalRangeField
def db_type(self, connection):
return 'numrange'
[docs]class FloatRangeField(RangeField):
system_check_deprecated_details = {
'msg': (
'FloatRangeField is deprecated and will be removed in Django 3.1.'
),
'hint': 'Use DecimalRangeField instead.',
'id': 'fields.W902',
}
base_field = models.FloatField
range_type = NumericRange
form_field = forms.FloatRangeField
def db_type(self, connection):
return 'numrange'
[docs]class DateTimeRangeField(RangeField):
base_field = models.DateTimeField
range_type = DateTimeTZRange
form_field = forms.DateTimeRangeField
def db_type(self, connection):
return 'tstzrange'
[docs]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(models.Lookup):
"""
Lookup for Date/DateTimeRange containment to cast the rhs to the correct
type.
"""
lookup_name = 'contains'
def process_rhs(self, compiler, connection):
# Transform rhs value for db lookup.
if isinstance(self.rhs, datetime.date):
output_field = models.DateTimeField() if isinstance(self.rhs, datetime.datetime) else models.DateField()
value = models.Value(self.rhs, output_field=output_field)
self.rhs = value.resolve_expression(compiler.query)
return super().process_rhs(compiler, connection)
def as_sql(self, compiler, connection):
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
params = lhs_params + rhs_params
# 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%s' % (lhs, rhs, cast_sql), params
DateRangeField.register_lookup(DateTimeRangeContains)
DateTimeRangeField.register_lookup(DateTimeRangeContains)
class RangeContainedBy(models.Lookup):
lookup_name = 'contained_by'
type_mapping = {
'integer': 'int4range',
'bigint': 'int8range',
'double precision': 'numrange',
'date': 'daterange',
'timestamp with time zone': 'tstzrange',
}
def as_sql(self, qn, connection):
field = self.lhs.output_field
if isinstance(field, models.FloatField):
sql = '%s::numeric <@ %s::{}'.format(self.type_mapping[field.db_type(connection)])
else:
sql = '%s <@ %s::{}'.format(self.type_mapping[field.db_type(connection)])
lhs, lhs_params = self.process_lhs(qn, connection)
rhs, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params
return sql % (lhs, rhs), 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.BigIntegerField.register_lookup(RangeContainedBy)
models.FloatField.register_lookup(RangeContainedBy)
@RangeField.register_lookup
class FullyLessThan(lookups.PostgresSimpleLookup):
lookup_name = 'fully_lt'
operator = '<<'
@RangeField.register_lookup
class FullGreaterThan(lookups.PostgresSimpleLookup):
lookup_name = 'fully_gt'
operator = '>>'
@RangeField.register_lookup
class NotLessThan(lookups.PostgresSimpleLookup):
lookup_name = 'not_lt'
operator = '&>'
@RangeField.register_lookup
class NotGreaterThan(lookups.PostgresSimpleLookup):
lookup_name = 'not_gt'
operator = '&<'
@RangeField.register_lookup
class AdjacentToLookup(lookups.PostgresSimpleLookup):
lookup_name = 'adjacent_to'
operator = '-|-'
@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()
