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from django.db.models.lookups import (
Exact, GreaterThan, GreaterThanOrEqual, In, IsNull, LessThan,
LessThanOrEqual,
)
class MultiColSource(object):
contains_aggregate = False
def __init__(self, alias, targets, sources, field):
self.targets, self.sources, self.field, self.alias = targets, sources, field, alias
self.output_field = self.field
def __repr__(self):
return "{}({}, {})".format(
self.__class__.__name__, self.alias, self.field)
def relabeled_clone(self, relabels):
return self.__class__(relabels.get(self.alias, self.alias),
self.targets, self.sources, self.field)
def get_normalized_value(value, lhs):
from django.db.models import Model
if isinstance(value, Model):
value_list = []
sources = lhs.output_field.get_path_info()[-1].target_fields
for source in sources:
while not isinstance(value, source.model) and source.remote_field:
source = source.remote_field.model._meta.get_field(source.remote_field.field_name)
try:
value_list.append(getattr(value, source.attname))
except AttributeError:
# A case like Restaurant.objects.filter(place=restaurant_instance),
# where place is a OneToOneField and the primary key of Restaurant.
return (value.pk,)
return tuple(value_list)
if not isinstance(value, tuple):
return (value,)
return value
class RelatedIn(In):
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource) and self.rhs_is_direct_value():
# If we get here, we are dealing with single-column relations.
self.rhs = [get_normalized_value(val, self.lhs)[0] for val in self.rhs]
# We need to run the related field's get_prep_lookup(). Consider case
# ForeignKey to IntegerField given value 'abc'. The ForeignKey itself
# doesn't have validation for non-integers, so we must run validation
# using the target field.
if hasattr(self.lhs.output_field, 'get_path_info'):
# Run the target field's get_prep_lookup. We can safely assume there is
# only one as we don't get to the direct value branch otherwise.
self.rhs = self.lhs.output_field.get_path_info()[-1].target_fields[-1].get_prep_lookup(
self.lookup_name, self.rhs)
return super(RelatedIn, self).get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
# For multicolumn lookups we need to build a multicolumn where clause.
# This clause is either a SubqueryConstraint (for values that need to be compiled to
# SQL) or a OR-combined list of (col1 = val1 AND col2 = val2 AND ...) clauses.
from django.db.models.sql.where import WhereNode, SubqueryConstraint, AND, OR
root_constraint = WhereNode(connector=OR)
if self.rhs_is_direct_value():
values = [get_normalized_value(value, self.lhs) for value in self.rhs]
for value in values:
value_constraint = WhereNode()
for source, target, val in zip(self.lhs.sources, self.lhs.targets, value):
lookup_class = target.get_lookup('exact')
lookup = lookup_class(target.get_col(self.lhs.alias, source), val)
value_constraint.add(lookup, AND)
root_constraint.add(value_constraint, OR)
else:
root_constraint.add(
SubqueryConstraint(
self.lhs.alias, [target.column for target in self.lhs.targets],
[source.name for source in self.lhs.sources], self.rhs),
AND)
return root_constraint.as_sql(compiler, connection)
else:
return super(RelatedIn, self).as_sql(compiler, connection)
class RelatedLookupMixin(object):
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource) and self.rhs_is_direct_value():
# If we get here, we are dealing with single-column relations.
self.rhs = get_normalized_value(self.rhs, self.lhs)[0]
# We need to run the related field's get_prep_lookup(). Consider case
# ForeignKey to IntegerField given value 'abc'. The ForeignKey itself
# doesn't have validation for non-integers, so we must run validation
# using the target field.
if hasattr(self.lhs.output_field, 'get_path_info'):
# Get the target field. We can safely assume there is only one
# as we don't get to the direct value branch otherwise.
self.rhs = self.lhs.output_field.get_path_info()[-1].target_fields[-1].get_prep_lookup(
self.lookup_name, self.rhs)
return super(RelatedLookupMixin, self).get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
assert self.rhs_is_direct_value()
self.rhs = get_normalized_value(self.rhs, self.lhs)
from django.db.models.sql.where import WhereNode, AND
root_constraint = WhereNode()
for target, source, val in zip(self.lhs.targets, self.lhs.sources, self.rhs):
lookup_class = target.get_lookup(self.lookup_name)
root_constraint.add(
lookup_class(target.get_col(self.lhs.alias, source), val), AND)
return root_constraint.as_sql(compiler, connection)
return super(RelatedLookupMixin, self).as_sql(compiler, connection)
class RelatedExact(RelatedLookupMixin, Exact):
pass
class RelatedLessThan(RelatedLookupMixin, LessThan):
pass
class RelatedGreaterThan(RelatedLookupMixin, GreaterThan):
pass
class RelatedGreaterThanOrEqual(RelatedLookupMixin, GreaterThanOrEqual):
pass
class RelatedLessThanOrEqual(RelatedLookupMixin, LessThanOrEqual):
pass
class RelatedIsNull(RelatedLookupMixin, IsNull):
pass
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