Fixed #16187 -- refactored ORM lookup system

Allowed users to specify which lookups or transforms ("nested lookus")
are available for fields. The implementation is now class based.

Squashed commit of the following:

commit fa7a7195f1
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 18 10:53:24 2014 +0200

    Added lookup registration API docs

commit eb1c8ce164
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Tue Jan 14 18:59:36 2014 +0200

    Release notes and other minor docs changes

commit 11501c29c9
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Jan 12 20:53:03 2014 +0200

    Forgot to add custom_lookups tests in prev commit

commit 83173b960e
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Jan 12 19:59:12 2014 +0200

    Renamed Extract -> Transform

commit 3b18d9f3a1
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Jan 12 19:51:53 2014 +0200

    Removed suggestion of temporary lookup registration from docs

commit 21d0c7631c
Merge: 2509006 f2dc442
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Jan 12 09:38:23 2014 -0800

    Merge pull request #2 from mjtamlyn/lookups_3

    Reworked custom lookups docs.

commit f2dc4429a1
Author: Marc Tamlyn <marc.tamlyn@gmail.com>
Date:   Sun Jan 12 13:15:05 2014 +0000

    Reworked custom lookups docs.

    Mostly just formatting and rewording, but also replaced the example
    using ``YearExtract`` to  use an example which is unlikely to ever be
    possible directly in the ORM.

commit 2509006506
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Jan 12 13:19:13 2014 +0200

    Removed unused import

commit 4fba5dfaa0
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 22:34:41 2014 +0200

    Added docs to index

commit 6d53963f37
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 22:10:24 2014 +0200

    Dead code removal

commit f9cc039007
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 19:00:43 2014 +0200

    A new try for docs

commit 33aa18a6e3
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 14:57:12 2014 +0200

    Renamed get_cols to get_group_by_cols

commit c7d5f8661b
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 14:45:53 2014 +0200

    Altered query string customization for backends vendors

    The new way is trying to call first method 'as_' + connection.vendor.
    If that doesn't exist, then call as_sql().

    Also altered how lookup registration is done. There is now
    RegisterLookupMixin class that is used by Field, Extract and
    sql.Aggregate. This allows one to register lookups for extracts and
    aggregates in the same way lookup registration is done for fields.

commit 90e7004ec1
Merge: 66649ff f7c2c0a
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 13:21:01 2014 +0200

    Merge branch 'master' into lookups_3

commit 66649ff891
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Jan 11 13:16:01 2014 +0200

    Some rewording in docs

commit 31b8faa627
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Dec 29 15:52:29 2013 +0200

    Cleanup based on review comments

commit 1016159f34
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Dec 28 18:37:04 2013 +0200

    Proof-of-concept fix for #16731

    Implemented only for SQLite and PostgreSQL, and only for startswith
    and istartswith lookups.

commit 193cd097ca
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Dec 28 17:57:58 2013 +0200

    Fixed #11722 -- iexact=F() produced invalid SQL

commit 08ed3c3b49
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Dec 21 23:59:52 2013 +0200

    Made Lookup and Extract available from django.db.models

commit b99c8d83c9
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Dec 21 23:06:29 2013 +0200

    Fixed review notes by Loic

commit 049eebc070
Merge: ed8fab7 b80a835
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Dec 21 22:53:10 2013 +0200

    Merge branch 'master' into lookups_3

    Conflicts:
    	django/db/models/fields/__init__.py
    	django/db/models/sql/compiler.py
    	django/db/models/sql/query.py
    	tests/null_queries/tests.py

commit ed8fab7fe8
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Dec 21 22:47:23 2013 +0200

    Made Extracts aware of full lookup path

commit 27a57b7aed
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Dec 1 21:10:11 2013 +0200

    Removed debugger import

commit 074e0f5aca
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Dec 1 21:02:16 2013 +0200

    GIS lookup support added

commit 760e28e72b
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Dec 1 20:04:31 2013 +0200

    Removed usage of Constraint, used Lookup instead

commit eac4776684
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Dec 1 02:22:30 2013 +0200

    Minor cleanup of Lookup API

commit 2adf50428d
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sun Dec 1 02:14:19 2013 +0200

    Added documentation, polished implementation

commit 32c04357a8
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Nov 30 23:10:15 2013 +0200

    Avoid OrderedDict creation on lookup aggregate check

commit 7c8b3a32cc
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Sat Nov 30 23:04:34 2013 +0200

    Implemented nested lookups

    But there is no support of using lookups outside filtering yet.

commit 4d219d4cde
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date:   Wed Nov 27 22:07:30 2013 +0200

    Initial implementation of custom lookups
This commit is contained in:
Anssi Kääriäinen 2014-01-18 11:09:43 +02:00
parent b87c59b04b
commit 20bab2cf9d
38 changed files with 1324 additions and 185 deletions

View File

@ -12,7 +12,7 @@ from django.db import models, router, transaction, DEFAULT_DB_ALIAS
from django.db.models import signals
from django.db.models.fields.related import ForeignObject, ForeignObjectRel
from django.db.models.related import PathInfo
from django.db.models.sql.where import Constraint
from django.db.models.sql.datastructures import Col
from django.forms import ModelForm, ALL_FIELDS
from django.forms.models import (BaseModelFormSet, modelformset_factory,
modelform_defines_fields)
@ -236,7 +236,8 @@ class GenericRelation(ForeignObject):
field = self.rel.to._meta.get_field_by_name(self.content_type_field_name)[0]
contenttype_pk = self.get_content_type().pk
cond = where_class()
cond.add((Constraint(remote_alias, field.column, field), 'exact', contenttype_pk), 'AND')
lookup = field.get_lookup('exact')(Col(remote_alias, field, field), contenttype_pk)
cond.add(lookup, 'AND')
return cond
def bulk_related_objects(self, objs, using=DEFAULT_DB_ALIAS):

View File

@ -49,9 +49,7 @@ class MySQLOperations(DatabaseOperations, BaseSpatialOperations):
return placeholder
def spatial_lookup_sql(self, lvalue, lookup_type, value, field, qn):
alias, col, db_type = lvalue
geo_col = '%s.%s' % (qn(alias), qn(col))
geo_col, db_type = lvalue
lookup_info = self.geometry_functions.get(lookup_type, False)
if lookup_info:

View File

@ -231,10 +231,7 @@ class OracleOperations(DatabaseOperations, BaseSpatialOperations):
def spatial_lookup_sql(self, lvalue, lookup_type, value, field, qn):
"Returns the SQL WHERE clause for use in Oracle spatial SQL construction."
alias, col, db_type = lvalue
# Getting the quoted table name as `geo_col`.
geo_col = '%s.%s' % (qn(alias), qn(col))
geo_col, db_type = lvalue
# See if a Oracle Geometry function matches the lookup type next
lookup_info = self.geometry_functions.get(lookup_type, False)

View File

@ -478,10 +478,7 @@ class PostGISOperations(DatabaseOperations, BaseSpatialOperations):
(alias, col, db_type), the lookup type string, lookup value, and
the geometry field.
"""
alias, col, db_type = lvalue
# Getting the quoted geometry column.
geo_col = '%s.%s' % (qn(alias), qn(col))
geo_col, db_type = lvalue
if lookup_type in self.geometry_operators:
if field.geography and not lookup_type in self.geography_operators:

View File

@ -324,10 +324,7 @@ class SpatiaLiteOperations(DatabaseOperations, BaseSpatialOperations):
[a tuple of (alias, column, db_type)], lookup type, lookup
value, the model field, and the quoting function.
"""
alias, col, db_type = lvalue
# Getting the quoted field as `geo_col`.
geo_col = '%s.%s' % (qn(alias), qn(col))
geo_col, db_type = lvalue
if lookup_type in self.geometry_functions:
# See if a SpatiaLite geometry function matches the lookup type.

View File

@ -0,0 +1,15 @@
from django.db.models.sql.constants import QUERY_TERMS
GIS_LOOKUPS = {
'bbcontains', 'bboverlaps', 'contained', 'contains',
'contains_properly', 'coveredby', 'covers', 'crosses', 'disjoint',
'distance_gt', 'distance_gte', 'distance_lt', 'distance_lte',
'dwithin', 'equals', 'exact',
'intersects', 'overlaps', 'relate', 'same_as', 'touches', 'within',
'left', 'right', 'overlaps_left', 'overlaps_right',
'overlaps_above', 'overlaps_below',
'strictly_above', 'strictly_below'
}
ALL_TERMS = GIS_LOOKUPS | QUERY_TERMS
__all__ = ['ALL_TERMS', 'GIS_LOOKUPS']

View File

@ -2,6 +2,8 @@ from django.db.models.fields import Field
from django.db.models.sql.expressions import SQLEvaluator
from django.utils.translation import ugettext_lazy as _
from django.contrib.gis import forms
from django.contrib.gis.db.models.constants import GIS_LOOKUPS
from django.contrib.gis.db.models.lookups import GISLookup
from django.contrib.gis.db.models.proxy import GeometryProxy
from django.contrib.gis.geometry.backend import Geometry, GeometryException
from django.utils import six
@ -284,6 +286,10 @@ class GeometryField(Field):
"""
return connection.ops.get_geom_placeholder(self, value)
for lookup_name in GIS_LOOKUPS:
lookup = type(lookup_name, (GISLookup,), {'lookup_name': lookup_name})
GeometryField.register_lookup(lookup)
# The OpenGIS Geometry Type Fields
class PointField(GeometryField):

View File

@ -0,0 +1,28 @@
from django.db.models.lookups import Lookup
from django.db.models.sql.expressions import SQLEvaluator
class GISLookup(Lookup):
def as_sql(self, qn, connection):
from django.contrib.gis.db.models.sql import GeoWhereNode
# We use the same approach as was used by GeoWhereNode. It would
# be a good idea to upgrade GIS to use similar code that is used
# for other lookups.
if isinstance(self.rhs, SQLEvaluator):
# Make sure the F Expression destination field exists, and
# set an `srid` attribute with the same as that of the
# destination.
geo_fld = GeoWhereNode._check_geo_field(self.rhs.opts, self.rhs.expression.name)
if not geo_fld:
raise ValueError('No geographic field found in expression.')
self.rhs.srid = geo_fld.srid
db_type = self.lhs.output_type.db_type(connection=connection)
params = self.lhs.output_type.get_db_prep_lookup(
self.lookup_name, self.rhs, connection=connection)
lhs_sql, lhs_params = self.process_lhs(qn, connection)
# lhs_params not currently supported.
assert not lhs_params
data = (lhs_sql, db_type)
spatial_sql, spatial_params = connection.ops.spatial_lookup_sql(
data, self.lookup_name, self.rhs, self.lhs.output_type, qn)
return spatial_sql, spatial_params + params

View File

@ -1,6 +1,7 @@
from django.db import connections
from django.db.models.query import sql
from django.contrib.gis.db.models.constants import ALL_TERMS
from django.contrib.gis.db.models.fields import GeometryField
from django.contrib.gis.db.models.sql import aggregates as gis_aggregates
from django.contrib.gis.db.models.sql.conversion import AreaField, DistanceField, GeomField
@ -9,19 +10,6 @@ from django.contrib.gis.geometry.backend import Geometry
from django.contrib.gis.measure import Area, Distance
ALL_TERMS = set([
'bbcontains', 'bboverlaps', 'contained', 'contains',
'contains_properly', 'coveredby', 'covers', 'crosses', 'disjoint',
'distance_gt', 'distance_gte', 'distance_lt', 'distance_lte',
'dwithin', 'equals', 'exact',
'intersects', 'overlaps', 'relate', 'same_as', 'touches', 'within',
'left', 'right', 'overlaps_left', 'overlaps_right',
'overlaps_above', 'overlaps_below',
'strictly_above', 'strictly_below'
])
ALL_TERMS.update(sql.constants.QUERY_TERMS)
class GeoQuery(sql.Query):
"""
A single spatial SQL query.

View File

@ -673,6 +673,9 @@ class BaseDatabaseFeatures(object):
# What kind of error does the backend throw when accessing closed cursor?
closed_cursor_error_class = ProgrammingError
# Does 'a' LIKE 'A' match?
has_case_insensitive_like = True
def __init__(self, connection):
self.connection = connection

View File

@ -62,6 +62,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
supports_combined_alters = True
nulls_order_largest = True
closed_cursor_error_class = InterfaceError
has_case_insensitive_like = False
class DatabaseWrapper(BaseDatabaseWrapper):
@ -83,6 +84,11 @@ class DatabaseWrapper(BaseDatabaseWrapper):
'iendswith': 'LIKE UPPER(%s)',
}
pattern_ops = {
'startswith': "LIKE %s || '%%%%'",
'istartswith': "LIKE UPPER(%s) || '%%%%'",
}
Database = Database
def __init__(self, *args, **kwargs):

View File

@ -334,6 +334,11 @@ class DatabaseWrapper(BaseDatabaseWrapper):
'iendswith': "LIKE %s ESCAPE '\\'",
}
pattern_ops = {
'startswith': "LIKE %s || '%%%%'",
'istartswith': "LIKE UPPER(%s) || '%%%%'",
}
Database = Database
def __init__(self, *args, **kwargs):

View File

@ -17,6 +17,7 @@ from django.db.models.fields.related import ( # NOQA
from django.db.models.fields.proxy import OrderWrt # NOQA
from django.db.models.deletion import ( # NOQA
CASCADE, PROTECT, SET, SET_NULL, SET_DEFAULT, DO_NOTHING, ProtectedError)
from django.db.models.lookups import Lookup, Transform # NOQA
from django.db.models import signals # NOQA

View File

@ -15,10 +15,11 @@ def refs_aggregate(lookup_parts, aggregates):
default annotation names we must check each prefix of the lookup_parts
for match.
"""
for i in range(len(lookup_parts) + 1):
if LOOKUP_SEP.join(lookup_parts[0:i]) in aggregates:
return True
return False
for n in range(len(lookup_parts) + 1):
level_n_lookup = LOOKUP_SEP.join(lookup_parts[0:n])
if level_n_lookup in aggregates:
return aggregates[level_n_lookup], lookup_parts[n:]
return False, ()
class Aggregate(object):

View File

@ -11,6 +11,7 @@ from itertools import tee
from django.apps import apps
from django.db import connection
from django.db.models.lookups import default_lookups, RegisterLookupMixin
from django.db.models.query_utils import QueryWrapper
from django.conf import settings
from django import forms
@ -80,7 +81,7 @@ def _empty(of_cls):
@total_ordering
class Field(object):
class Field(RegisterLookupMixin):
"""Base class for all field types"""
# Designates whether empty strings fundamentally are allowed at the
@ -101,6 +102,7 @@ class Field(object):
'unique': _('%(model_name)s with this %(field_label)s '
'already exists.'),
}
class_lookups = default_lookups.copy()
# Generic field type description, usually overridden by subclasses
def _description(self):
@ -514,8 +516,7 @@ class Field(object):
except ValueError:
raise ValueError("The __year lookup type requires an integer "
"argument")
raise TypeError("Field has invalid lookup: %s" % lookup_type)
return self.get_prep_value(value)
def get_db_prep_lookup(self, lookup_type, value, connection,
prepared=False):
@ -564,6 +565,8 @@ class Field(object):
return connection.ops.year_lookup_bounds_for_date_field(value)
else:
return [value] # this isn't supposed to happen
else:
return [value]
def has_default(self):
"""

View File

@ -5,9 +5,11 @@ from django.db.backends import utils
from django.db.models import signals, Q
from django.db.models.fields import (AutoField, Field, IntegerField,
PositiveIntegerField, PositiveSmallIntegerField, FieldDoesNotExist)
from django.db.models.lookups import IsNull
from django.db.models.related import RelatedObject, PathInfo
from django.db.models.query import QuerySet
from django.db.models.deletion import CASCADE
from django.db.models.sql.datastructures import Col
from django.utils.encoding import smart_text
from django.utils import six
from django.utils.deprecation import RenameMethodsBase
@ -987,6 +989,11 @@ class ForeignObjectRel(object):
# example custom multicolumn joins currently have no remote field).
self.field_name = None
def get_lookup_constraint(self, constraint_class, alias, targets, sources, lookup_type,
raw_value):
return self.field.get_lookup_constraint(constraint_class, alias, targets, sources,
lookup_type, raw_value)
class ManyToOneRel(ForeignObjectRel):
def __init__(self, field, to, field_name, related_name=None, limit_choices_to=None,
@ -1193,14 +1200,16 @@ class ForeignObject(RelatedField):
pathinfos = [PathInfo(from_opts, opts, (opts.pk,), self.rel, not self.unique, False)]
return pathinfos
def get_lookup_constraint(self, constraint_class, alias, targets, sources, lookup_type,
def get_lookup_constraint(self, constraint_class, alias, targets, sources, lookups,
raw_value):
from django.db.models.sql.where import SubqueryConstraint, Constraint, AND, OR
from django.db.models.sql.where import SubqueryConstraint, AND, OR
root_constraint = constraint_class()
assert len(targets) == len(sources)
if len(lookups) > 1:
raise exceptions.FieldError('Relation fields do not support nested lookups')
lookup_type = lookups[0]
def get_normalized_value(value):
from django.db.models import Model
if isinstance(value, Model):
value_list = []
@ -1221,28 +1230,27 @@ class ForeignObject(RelatedField):
[source.name for source in sources], raw_value),
AND)
elif lookup_type == 'isnull':
root_constraint.add(
(Constraint(alias, targets[0].column, targets[0]), lookup_type, raw_value), AND)
root_constraint.add(IsNull(Col(alias, targets[0], sources[0]), raw_value), AND)
elif (lookup_type == 'exact' or (lookup_type in ['gt', 'lt', 'gte', 'lte']
and not is_multicolumn)):
value = get_normalized_value(raw_value)
for index, source in enumerate(sources):
for target, source, val in zip(targets, sources, value):
lookup_class = target.get_lookup(lookup_type)
root_constraint.add(
(Constraint(alias, targets[index].column, sources[index]), lookup_type,
value[index]), AND)
lookup_class(Col(alias, target, source), val), AND)
elif lookup_type in ['range', 'in'] and not is_multicolumn:
values = [get_normalized_value(value) for value in raw_value]
value = [val[0] for val in values]
root_constraint.add(
(Constraint(alias, targets[0].column, sources[0]), lookup_type, value), AND)
lookup_class = targets[0].get_lookup(lookup_type)
root_constraint.add(lookup_class(Col(alias, targets[0], sources[0]), value), AND)
elif lookup_type == 'in':
values = [get_normalized_value(value) for value in raw_value]
for value in values:
value_constraint = constraint_class()
for index, target in enumerate(targets):
value_constraint.add(
(Constraint(alias, target.column, sources[index]), 'exact', value[index]),
AND)
for source, target, val in zip(sources, targets, value):
lookup_class = target.get_lookup('exact')
lookup = lookup_class(Col(alias, target, source), val)
value_constraint.add(lookup, AND)
root_constraint.add(value_constraint, OR)
else:
raise TypeError('Related Field got invalid lookup: %s' % lookup_type)

317
django/db/models/lookups.py Normal file
View File

@ -0,0 +1,317 @@
from copy import copy
import inspect
from django.conf import settings
from django.utils import timezone
from django.utils.functional import cached_property
class RegisterLookupMixin(object):
def get_lookup(self, lookup_name):
try:
return self.class_lookups[lookup_name]
except KeyError:
# To allow for inheritance, check parent class class lookups.
for parent in inspect.getmro(self.__class__):
if not 'class_lookups' in parent.__dict__:
continue
if lookup_name in parent.class_lookups:
return parent.class_lookups[lookup_name]
except AttributeError:
# This class didn't have any class_lookups
pass
if hasattr(self, 'output_type'):
return self.output_type.get_lookup(lookup_name)
return None
@classmethod
def register_lookup(cls, lookup):
if not 'class_lookups' in cls.__dict__:
cls.class_lookups = {}
cls.class_lookups[lookup.lookup_name] = lookup
@classmethod
def _unregister_lookup(cls, lookup):
"""
Removes given lookup from cls lookups. Meant to be used in
tests only.
"""
del cls.class_lookups[lookup.lookup_name]
class Transform(RegisterLookupMixin):
def __init__(self, lhs, lookups):
self.lhs = lhs
self.init_lookups = lookups[:]
def as_sql(self, qn, connection):
raise NotImplementedError
@cached_property
def output_type(self):
return self.lhs.output_type
def relabeled_clone(self, relabels):
return self.__class__(self.lhs.relabeled_clone(relabels))
def get_group_by_cols(self):
return self.lhs.get_group_by_cols()
class Lookup(RegisterLookupMixin):
lookup_name = None
def __init__(self, lhs, rhs):
self.lhs, self.rhs = lhs, rhs
self.rhs = self.get_prep_lookup()
def get_prep_lookup(self):
return self.lhs.output_type.get_prep_lookup(self.lookup_name, self.rhs)
def get_db_prep_lookup(self, value, connection):
return (
'%s', self.lhs.output_type.get_db_prep_lookup(
self.lookup_name, value, connection, prepared=True))
def process_lhs(self, qn, connection, lhs=None):
lhs = lhs or self.lhs
return qn.compile(lhs)
def process_rhs(self, qn, connection, rhs=None):
value = rhs or self.rhs
# Due to historical reasons there are a couple of different
# ways to produce sql here. get_compiler is likely a Query
# instance, _as_sql QuerySet and as_sql just something with
# as_sql. Finally the value can of course be just plain
# Python value.
if hasattr(value, 'get_compiler'):
value = value.get_compiler(connection=connection)
if hasattr(value, 'as_sql'):
sql, params = qn.compile(value)
return '(' + sql + ')', params
if hasattr(value, '_as_sql'):
sql, params = value._as_sql(connection=connection)
return '(' + sql + ')', params
else:
return self.get_db_prep_lookup(value, connection)
def relabeled_clone(self, relabels):
new = copy(self)
new.lhs = new.lhs.relabeled_clone(relabels)
if hasattr(new.rhs, 'relabeled_clone'):
new.rhs = new.rhs.relabeled_clone(relabels)
return new
def get_group_by_cols(self):
cols = self.lhs.get_group_by_cols()
if hasattr(self.rhs, 'get_group_by_cols'):
cols.extend(self.rhs.get_group_by_cols())
return cols
def as_sql(self, qn, connection):
raise NotImplementedError
class BuiltinLookup(Lookup):
def as_sql(self, qn, connection):
lhs_sql, params = self.process_lhs(qn, connection)
field_internal_type = self.lhs.output_type.get_internal_type()
db_type = self.lhs.output_type
lhs_sql = connection.ops.field_cast_sql(db_type, field_internal_type) % lhs_sql
lhs_sql = connection.ops.lookup_cast(self.lookup_name) % lhs_sql
rhs_sql, rhs_params = self.process_rhs(qn, connection)
params.extend(rhs_params)
operator_plus_rhs = self.get_rhs_op(connection, rhs_sql)
return '%s %s' % (lhs_sql, operator_plus_rhs), params
def get_rhs_op(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
default_lookups = {}
class Exact(BuiltinLookup):
lookup_name = 'exact'
default_lookups['exact'] = Exact
class IExact(BuiltinLookup):
lookup_name = 'iexact'
default_lookups['iexact'] = IExact
class Contains(BuiltinLookup):
lookup_name = 'contains'
default_lookups['contains'] = Contains
class IContains(BuiltinLookup):
lookup_name = 'icontains'
default_lookups['icontains'] = IContains
class GreaterThan(BuiltinLookup):
lookup_name = 'gt'
default_lookups['gt'] = GreaterThan
class GreaterThanOrEqual(BuiltinLookup):
lookup_name = 'gte'
default_lookups['gte'] = GreaterThanOrEqual
class LessThan(BuiltinLookup):
lookup_name = 'lt'
default_lookups['lt'] = LessThan
class LessThanOrEqual(BuiltinLookup):
lookup_name = 'lte'
default_lookups['lte'] = LessThanOrEqual
class In(BuiltinLookup):
lookup_name = 'in'
def get_db_prep_lookup(self, value, connection):
params = self.lhs.output_type.get_db_prep_lookup(
self.lookup_name, value, connection, prepared=True)
if not params:
# TODO: check why this leads to circular import
from django.db.models.sql.datastructures import EmptyResultSet
raise EmptyResultSet
placeholder = '(' + ', '.join('%s' for p in params) + ')'
return (placeholder, params)
def get_rhs_op(self, connection, rhs):
return 'IN %s' % rhs
default_lookups['in'] = In
class PatternLookup(BuiltinLookup):
def get_rhs_op(self, connection, rhs):
# Assume we are in startswith. We need to produce SQL like:
# col LIKE %s, ['thevalue%']
# For python values we can (and should) do that directly in Python,
# but if the value is for example reference to other column, then
# we need to add the % pattern match to the lookup by something like
# col LIKE othercol || '%%'
# So, for Python values we don't need any special pattern, but for
# SQL reference values we need the correct pattern added.
value = self.rhs
if (hasattr(value, 'get_compiler') or hasattr(value, 'as_sql')
or hasattr(value, '_as_sql')):
return connection.pattern_ops[self.lookup_name] % rhs
else:
return super(PatternLookup, self).get_rhs_op(connection, rhs)
class StartsWith(PatternLookup):
lookup_name = 'startswith'
default_lookups['startswith'] = StartsWith
class IStartsWith(PatternLookup):
lookup_name = 'istartswith'
default_lookups['istartswith'] = IStartsWith
class EndsWith(BuiltinLookup):
lookup_name = 'endswith'
default_lookups['endswith'] = EndsWith
class IEndsWith(BuiltinLookup):
lookup_name = 'iendswith'
default_lookups['iendswith'] = IEndsWith
class Between(BuiltinLookup):
def get_rhs_op(self, connection, rhs):
return "BETWEEN %s AND %s" % (rhs, rhs)
class Year(Between):
lookup_name = 'year'
default_lookups['year'] = Year
class Range(Between):
lookup_name = 'range'
default_lookups['range'] = Range
class DateLookup(BuiltinLookup):
def process_lhs(self, qn, connection):
lhs, params = super(DateLookup, self).process_lhs(qn, connection)
tzname = timezone.get_current_timezone_name() if settings.USE_TZ else None
sql, tz_params = connection.ops.datetime_extract_sql(self.extract_type, lhs, tzname)
return connection.ops.lookup_cast(self.lookup_name) % sql, tz_params
def get_rhs_op(self, connection, rhs):
return '= %s' % rhs
class Month(DateLookup):
lookup_name = 'month'
extract_type = 'month'
default_lookups['month'] = Month
class Day(DateLookup):
lookup_name = 'day'
extract_type = 'day'
default_lookups['day'] = Day
class WeekDay(DateLookup):
lookup_name = 'week_day'
extract_type = 'week_day'
default_lookups['week_day'] = WeekDay
class Hour(DateLookup):
lookup_name = 'hour'
extract_type = 'hour'
default_lookups['hour'] = Hour
class Minute(DateLookup):
lookup_name = 'minute'
extract_type = 'minute'
default_lookups['minute'] = Minute
class Second(DateLookup):
lookup_name = 'second'
extract_type = 'second'
default_lookups['second'] = Second
class IsNull(BuiltinLookup):
lookup_name = 'isnull'
def as_sql(self, qn, connection):
sql, params = qn.compile(self.lhs)
if self.rhs:
return "%s IS NULL" % sql, params
else:
return "%s IS NOT NULL" % sql, params
default_lookups['isnull'] = IsNull
class Search(BuiltinLookup):
lookup_name = 'search'
default_lookups['search'] = Search
class Regex(BuiltinLookup):
lookup_name = 'regex'
default_lookups['regex'] = Regex
class IRegex(BuiltinLookup):
lookup_name = 'iregex'
default_lookups['iregex'] = IRegex

View File

@ -4,6 +4,7 @@ Classes to represent the default SQL aggregate functions
import copy
from django.db.models.fields import IntegerField, FloatField
from django.db.models.lookups import RegisterLookupMixin
__all__ = ['Aggregate', 'Avg', 'Count', 'Max', 'Min', 'StdDev', 'Sum', 'Variance']
@ -14,7 +15,7 @@ ordinal_aggregate_field = IntegerField()
computed_aggregate_field = FloatField()
class Aggregate(object):
class Aggregate(RegisterLookupMixin):
"""
Default SQL Aggregate.
"""
@ -93,6 +94,13 @@ class Aggregate(object):
return self.sql_template % substitutions, params
def get_group_by_cols(self):
return []
@property
def output_type(self):
return self.field
class Avg(Aggregate):
is_computed = True

View File

@ -45,7 +45,7 @@ class SQLCompiler(object):
if self.query.select_related and not self.query.related_select_cols:
self.fill_related_selections()
def quote_name_unless_alias(self, name):
def __call__(self, name):
"""
A wrapper around connection.ops.quote_name that doesn't quote aliases
for table names. This avoids problems with some SQL dialects that treat
@ -61,6 +61,22 @@ class SQLCompiler(object):
self.quote_cache[name] = r
return r
def quote_name_unless_alias(self, name):
"""
A wrapper around connection.ops.quote_name that doesn't quote aliases
for table names. This avoids problems with some SQL dialects that treat
quoted strings specially (e.g. PostgreSQL).
"""
return self(name)
def compile(self, node):
vendor_impl = getattr(
node, 'as_' + self.connection.vendor, None)
if vendor_impl:
return vendor_impl(self, self.connection)
else:
return node.as_sql(self, self.connection)
def as_sql(self, with_limits=True, with_col_aliases=False):
"""
Creates the SQL for this query. Returns the SQL string and list of
@ -88,11 +104,9 @@ class SQLCompiler(object):
# docstring of get_from_clause() for details.
from_, f_params = self.get_from_clause()
qn = self.quote_name_unless_alias
where, w_params = self.query.where.as_sql(qn=qn, connection=self.connection)
having, h_params = self.query.having.as_sql(qn=qn, connection=self.connection)
having_group_by = self.query.having.get_cols()
where, w_params = self.compile(self.query.where)
having, h_params = self.compile(self.query.having)
having_group_by = self.query.having.get_group_by_cols()
params = []
for val in six.itervalues(self.query.extra_select):
params.extend(val[1])
@ -180,7 +194,7 @@ class SQLCompiler(object):
(without the table names) are given unique aliases. This is needed in
some cases to avoid ambiguity with nested queries.
"""
qn = self.quote_name_unless_alias
qn = self
qn2 = self.connection.ops.quote_name
result = ['(%s) AS %s' % (col[0], qn2(alias)) for alias, col in six.iteritems(self.query.extra_select)]
params = []
@ -213,7 +227,7 @@ class SQLCompiler(object):
aliases.add(r)
col_aliases.add(col[1])
else:
col_sql, col_params = col.as_sql(qn, self.connection)
col_sql, col_params = self.compile(col)
result.append(col_sql)
params.extend(col_params)
@ -229,7 +243,7 @@ class SQLCompiler(object):
max_name_length = self.connection.ops.max_name_length()
for alias, aggregate in self.query.aggregate_select.items():
agg_sql, agg_params = aggregate.as_sql(qn, self.connection)
agg_sql, agg_params = self.compile(aggregate)
if alias is None:
result.append(agg_sql)
else:
@ -267,7 +281,7 @@ class SQLCompiler(object):
result = []
if opts is None:
opts = self.query.get_meta()
qn = self.quote_name_unless_alias
qn = self
qn2 = self.connection.ops.quote_name
aliases = set()
only_load = self.deferred_to_columns()
@ -319,7 +333,7 @@ class SQLCompiler(object):
Note that this method can alter the tables in the query, and thus it
must be called before get_from_clause().
"""
qn = self.quote_name_unless_alias
qn = self
qn2 = self.connection.ops.quote_name
result = []
opts = self.query.get_meta()
@ -352,7 +366,7 @@ class SQLCompiler(object):
ordering = (self.query.order_by
or self.query.get_meta().ordering
or [])
qn = self.quote_name_unless_alias
qn = self
qn2 = self.connection.ops.quote_name
distinct = self.query.distinct
select_aliases = self._select_aliases
@ -490,7 +504,7 @@ class SQLCompiler(object):
ordering and distinct must be done first.
"""
result = []
qn = self.quote_name_unless_alias
qn = self
qn2 = self.connection.ops.quote_name
first = True
from_params = []
@ -508,8 +522,7 @@ class SQLCompiler(object):
extra_cond = join_field.get_extra_restriction(
self.query.where_class, alias, lhs)
if extra_cond:
extra_sql, extra_params = extra_cond.as_sql(
qn, self.connection)
extra_sql, extra_params = self.compile(extra_cond)
extra_sql = 'AND (%s)' % extra_sql
from_params.extend(extra_params)
else:
@ -541,7 +554,7 @@ class SQLCompiler(object):
"""
Returns a tuple representing the SQL elements in the "group by" clause.
"""
qn = self.quote_name_unless_alias
qn = self
result, params = [], []
if self.query.group_by is not None:
select_cols = self.query.select + self.query.related_select_cols
@ -560,7 +573,7 @@ class SQLCompiler(object):
if isinstance(col, (list, tuple)):
sql = '%s.%s' % (qn(col[0]), qn(col[1]))
elif hasattr(col, 'as_sql'):
sql, col_params = col.as_sql(qn, self.connection)
self.compile(col)
else:
sql = '(%s)' % str(col)
if sql not in seen:
@ -784,7 +797,7 @@ class SQLCompiler(object):
return result
def as_subquery_condition(self, alias, columns, qn):
inner_qn = self.quote_name_unless_alias
inner_qn = self
qn2 = self.connection.ops.quote_name
if len(columns) == 1:
sql, params = self.as_sql()
@ -895,9 +908,9 @@ class SQLDeleteCompiler(SQLCompiler):
"""
assert len(self.query.tables) == 1, \
"Can only delete from one table at a time."
qn = self.quote_name_unless_alias
qn = self
result = ['DELETE FROM %s' % qn(self.query.tables[0])]
where, params = self.query.where.as_sql(qn=qn, connection=self.connection)
where, params = self.compile(self.query.where)
if where:
result.append('WHERE %s' % where)
return ' '.join(result), tuple(params)
@ -913,7 +926,7 @@ class SQLUpdateCompiler(SQLCompiler):
if not self.query.values:
return '', ()
table = self.query.tables[0]
qn = self.quote_name_unless_alias
qn = self
result = ['UPDATE %s' % qn(table)]
result.append('SET')
values, update_params = [], []
@ -933,7 +946,7 @@ class SQLUpdateCompiler(SQLCompiler):
val = SQLEvaluator(val, self.query, allow_joins=False)
name = field.column
if hasattr(val, 'as_sql'):
sql, params = val.as_sql(qn, self.connection)
sql, params = self.compile(val)
values.append('%s = %s' % (qn(name), sql))
update_params.extend(params)
elif val is not None:
@ -944,7 +957,7 @@ class SQLUpdateCompiler(SQLCompiler):
if not values:
return '', ()
result.append(', '.join(values))
where, params = self.query.where.as_sql(qn=qn, connection=self.connection)
where, params = self.compile(self.query.where)
if where:
result.append('WHERE %s' % where)
return ' '.join(result), tuple(update_params + params)
@ -1024,11 +1037,11 @@ class SQLAggregateCompiler(SQLCompiler):
parameters.
"""
if qn is None:
qn = self.quote_name_unless_alias
qn = self
sql, params = [], []
for aggregate in self.query.aggregate_select.values():
agg_sql, agg_params = aggregate.as_sql(qn, self.connection)
agg_sql, agg_params = self.compile(aggregate)
sql.append(agg_sql)
params.extend(agg_params)
sql = ', '.join(sql)

View File

@ -5,19 +5,28 @@ the SQL domain.
class Col(object):
def __init__(self, alias, col):
self.alias = alias
self.col = col
def __init__(self, alias, target, source):
self.alias, self.target, self.source = alias, target, source
def as_sql(self, qn, connection):
return '%s.%s' % (qn(self.alias), self.col), []
return "%s.%s" % (qn(self.alias), qn(self.target.column)), []
@property
def output_type(self):
return self.source
def relabeled_clone(self, relabels):
return self.__class__(relabels.get(self.alias, self.alias), self.target, self.source)
def get_group_by_cols(self):
return [(self.alias, self.target.column)]
def get_lookup(self, name):
return self.output_type.get_lookup(name)
def prepare(self):
return self
def relabeled_clone(self, relabels):
return self.__class__(relabels.get(self.alias, self.alias), self.col)
class EmptyResultSet(Exception):
pass

View File

@ -24,11 +24,11 @@ class SQLEvaluator(object):
(change_map.get(col[0], col[0]), col[1])))
return clone
def get_cols(self):
def get_group_by_cols(self):
cols = []
for node, col in self.cols:
if hasattr(node, 'get_cols'):
cols.extend(node.get_cols())
if hasattr(node, 'get_group_by_cols'):
cols.extend(node.get_group_by_cols())
elif isinstance(col, tuple):
cols.append(col)
return cols

View File

@ -19,6 +19,7 @@ from django.db.models.constants import LOOKUP_SEP
from django.db.models.aggregates import refs_aggregate
from django.db.models.expressions import ExpressionNode
from django.db.models.fields import FieldDoesNotExist
from django.db.models.lookups import Transform
from django.db.models.query_utils import Q
from django.db.models.related import PathInfo
from django.db.models.sql import aggregates as base_aggregates_module
@ -1028,13 +1029,16 @@ class Query(object):
# Add the aggregate to the query
aggregate.add_to_query(self, alias, col=col, source=source, is_summary=is_summary)
def prepare_lookup_value(self, value, lookup_type, can_reuse):
def prepare_lookup_value(self, value, lookups, can_reuse):
# Default lookup if none given is exact.
if len(lookups) == 0:
lookups = ['exact']
# Interpret '__exact=None' as the sql 'is NULL'; otherwise, reject all
# uses of None as a query value.
if value is None:
if lookup_type not in ('exact', 'iexact'):
if lookups[-1] not in ('exact', 'iexact'):
raise ValueError("Cannot use None as a query value")
lookup_type = 'isnull'
lookups[-1] = 'isnull'
value = True
elif callable(value):
warnings.warn(
@ -1055,40 +1059,54 @@ class Query(object):
# stage. Using DEFAULT_DB_ALIAS isn't nice, but it is the best we
# can do here. Similar thing is done in is_nullable(), too.
if (connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls and
lookup_type == 'exact' and value == ''):
lookups[-1] == 'exact' and value == ''):
value = True
lookup_type = 'isnull'
return value, lookup_type
lookups[-1] = ['isnull']
return value, lookups
def solve_lookup_type(self, lookup):
"""
Solve the lookup type from the lookup (eg: 'foobar__id__icontains')
"""
lookup_type = 'exact' # Default lookup type
lookup_parts = lookup.split(LOOKUP_SEP)
num_parts = len(lookup_parts)
if (len(lookup_parts) > 1 and lookup_parts[-1] in self.query_terms
and (not self._aggregates or lookup not in self._aggregates)):
# Traverse the lookup query to distinguish related fields from
# lookup types.
lookup_model = self.model
for counter, field_name in enumerate(lookup_parts):
try:
lookup_field = lookup_model._meta.get_field(field_name)
except FieldDoesNotExist:
# Not a field. Bail out.
lookup_type = lookup_parts.pop()
break
# Unless we're at the end of the list of lookups, let's attempt
# to continue traversing relations.
if (counter + 1) < num_parts:
try:
lookup_model = lookup_field.rel.to
except AttributeError:
# Not a related field. Bail out.
lookup_type = lookup_parts.pop()
break
return lookup_type, lookup_parts
lookup_splitted = lookup.split(LOOKUP_SEP)
if self._aggregates:
aggregate, aggregate_lookups = refs_aggregate(lookup_splitted, self.aggregates)
if aggregate:
return aggregate_lookups, (), aggregate
_, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
field_parts = lookup_splitted[0:len(lookup_splitted) - len(lookup_parts)]
if len(lookup_parts) == 0:
lookup_parts = ['exact']
elif len(lookup_parts) > 1:
if not field_parts:
raise FieldError(
'Invalid lookup "%s" for model %s".' %
(lookup, self.get_meta().model.__name__))
return lookup_parts, field_parts, False
def build_lookup(self, lookups, lhs, rhs):
lookups = lookups[:]
while lookups:
lookup = lookups[0]
next = lhs.get_lookup(lookup)
if next:
if len(lookups) == 1:
# This was the last lookup, so return value lookup.
if issubclass(next, Transform):
lookups.append('exact')
lhs = next(lhs, lookups)
else:
return next(lhs, rhs)
else:
lhs = next(lhs, lookups)
# A field's get_lookup() can return None to opt for backwards
# compatibility path.
elif len(lookups) > 2:
raise FieldError(
"Unsupported lookup for field '%s'" % lhs.output_type.name)
else:
return None
lookups = lookups[1:]
def build_filter(self, filter_expr, branch_negated=False, current_negated=False,
can_reuse=None, connector=AND):
@ -1118,21 +1136,24 @@ class Query(object):
is responsible for unreffing the joins used.
"""
arg, value = filter_expr
lookup_type, parts = self.solve_lookup_type(arg)
if not parts:
if not arg:
raise FieldError("Cannot parse keyword query %r" % arg)
lookups, parts, reffed_aggregate = self.solve_lookup_type(arg)
# Work out the lookup type and remove it from the end of 'parts',
# if necessary.
value, lookup_type = self.prepare_lookup_value(value, lookup_type, can_reuse)
value, lookups = self.prepare_lookup_value(value, lookups, can_reuse)
used_joins = getattr(value, '_used_joins', [])
clause = self.where_class()
if self._aggregates:
for alias, aggregate in self.aggregates.items():
if alias in (parts[0], LOOKUP_SEP.join(parts)):
clause.add((aggregate, lookup_type, value), AND)
return clause, []
if reffed_aggregate:
condition = self.build_lookup(lookups, reffed_aggregate, value)
if not condition:
# Backwards compat for custom lookups
assert len(lookups) == 1
condition = (reffed_aggregate, lookups[0], value)
clause.add(condition, AND)
return clause, []
opts = self.get_meta()
alias = self.get_initial_alias()
@ -1154,11 +1175,31 @@ class Query(object):
targets, alias, join_list = self.trim_joins(sources, join_list, path)
if hasattr(field, 'get_lookup_constraint'):
constraint = field.get_lookup_constraint(self.where_class, alias, targets, sources,
lookup_type, value)
# For now foreign keys get special treatment. This should be
# refactored when composite fields lands.
condition = field.get_lookup_constraint(self.where_class, alias, targets, sources,
lookups, value)
lookup_type = lookups[-1]
else:
constraint = (Constraint(alias, targets[0].column, field), lookup_type, value)
clause.add(constraint, AND)
assert(len(targets) == 1)
col = Col(alias, targets[0], field)
condition = self.build_lookup(lookups, col, value)
if not condition:
# Backwards compat for custom lookups
if lookups[0] not in self.query_terms:
raise FieldError(
"Join on field '%s' not permitted. Did you "
"misspell '%s' for the lookup type?" %
(col.output_type.name, lookups[0]))
if len(lookups) > 1:
raise FieldError("Nested lookup '%s' not supported." %
LOOKUP_SEP.join(lookups))
condition = (Constraint(alias, targets[0].column, field), lookups[0], value)
lookup_type = lookups[-1]
else:
lookup_type = condition.lookup_name
clause.add(condition, AND)
require_outer = lookup_type == 'isnull' and value is True and not current_negated
if current_negated and (lookup_type != 'isnull' or value is False):
@ -1175,7 +1216,8 @@ class Query(object):
# (col IS NULL OR col != someval)
# <=>
# NOT (col IS NOT NULL AND col = someval).
clause.add((Constraint(alias, targets[0].column, None), 'isnull', False), AND)
lookup_class = targets[0].get_lookup('isnull')
clause.add(lookup_class(Col(alias, targets[0], sources[0]), False), AND)
return clause, used_joins if not require_outer else ()
def add_filter(self, filter_clause):
@ -1189,7 +1231,7 @@ class Query(object):
if not self._aggregates:
return False
if not isinstance(obj, Node):
return (refs_aggregate(obj[0].split(LOOKUP_SEP), self.aggregates)
return (refs_aggregate(obj[0].split(LOOKUP_SEP), self.aggregates)[0]
or (hasattr(obj[1], 'contains_aggregate')
and obj[1].contains_aggregate(self.aggregates)))
return any(self.need_having(c) for c in obj.children)
@ -1277,7 +1319,7 @@ class Query(object):
needed_inner = joinpromoter.update_join_types(self)
return target_clause, needed_inner
def names_to_path(self, names, opts, allow_many):
def names_to_path(self, names, opts, allow_many=True, fail_on_missing=False):
"""
Walks the names path and turns them PathInfo tuples. Note that a
single name in 'names' can generate multiple PathInfos (m2m for
@ -1297,9 +1339,10 @@ class Query(object):
try:
field, model, direct, m2m = opts.get_field_by_name(name)
except FieldDoesNotExist:
available = opts.get_all_field_names() + list(self.aggregate_select)
raise FieldError("Cannot resolve keyword %r into field. "
"Choices are: %s" % (name, ", ".join(available)))
# We didn't found the current field, so move position back
# one step.
pos -= 1
break
# Check if we need any joins for concrete inheritance cases (the
# field lives in parent, but we are currently in one of its
# children)
@ -1334,15 +1377,14 @@ class Query(object):
final_field = field
targets = (field,)
break
if pos == -1 or (fail_on_missing and pos + 1 != len(names)):
self.raise_field_error(opts, name)
return path, final_field, targets, names[pos + 1:]
if pos != len(names) - 1:
if pos == len(names) - 2:
raise FieldError(
"Join on field %r not permitted. Did you misspell %r for "
"the lookup type?" % (name, names[pos + 1]))
else:
raise FieldError("Join on field %r not permitted." % name)
return path, final_field, targets
def raise_field_error(self, opts, name):
available = opts.get_all_field_names() + list(self.aggregate_select)
raise FieldError("Cannot resolve keyword %r into field. "
"Choices are: %s" % (name, ", ".join(available)))
def setup_joins(self, names, opts, alias, can_reuse=None, allow_many=True):
"""
@ -1371,8 +1413,9 @@ class Query(object):
"""
joins = [alias]
# First, generate the path for the names
path, final_field, targets = self.names_to_path(
names, opts, allow_many)
path, final_field, targets, rest = self.names_to_path(
names, opts, allow_many, fail_on_missing=True)
# Then, add the path to the query's joins. Note that we can't trim
# joins at this stage - we will need the information about join type
# of the trimmed joins.
@ -1387,8 +1430,6 @@ class Query(object):
alias = self.join(
connection, reuse=reuse, nullable=nullable, join_field=join.join_field)
joins.append(alias)
if hasattr(final_field, 'field'):
final_field = final_field.field
return final_field, targets, opts, joins, path
def trim_joins(self, targets, joins, path):
@ -1451,17 +1492,19 @@ class Query(object):
# nothing
alias, col = query.select[0].col
if self.is_nullable(query.select[0].field):
query.where.add((Constraint(alias, col, query.select[0].field), 'isnull', False), AND)
lookup_class = query.select[0].field.get_lookup('isnull')
lookup = lookup_class(Col(alias, query.select[0].field, query.select[0].field), False)
query.where.add(lookup, AND)
if alias in can_reuse:
pk = query.select[0].field.model._meta.pk
select_field = query.select[0].field
pk = select_field.model._meta.pk
# Need to add a restriction so that outer query's filters are in effect for
# the subquery, too.
query.bump_prefix(self)
query.where.add(
(Constraint(query.select[0].col[0], pk.column, pk),
'exact', Col(alias, pk.column)),
AND
)
lookup_class = select_field.get_lookup('exact')
lookup = lookup_class(Col(query.select[0].col[0], pk, pk),
Col(alias, pk, pk))
query.where.add(lookup, AND)
condition, needed_inner = self.build_filter(
('%s__in' % trimmed_prefix, query),

View File

@ -5,12 +5,12 @@ Query subclasses which provide extra functionality beyond simple data retrieval.
from django.conf import settings
from django.core.exceptions import FieldError
from django.db import connections
from django.db.models.query_utils import Q
from django.db.models.constants import LOOKUP_SEP
from django.db.models.fields import DateField, DateTimeField, FieldDoesNotExist
from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE, SelectInfo
from django.db.models.sql.datastructures import Date, DateTime
from django.db.models.sql.query import Query
from django.db.models.sql.where import AND, Constraint
from django.utils import six
from django.utils import timezone
@ -42,10 +42,10 @@ class DeleteQuery(Query):
if not field:
field = self.get_meta().pk
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
where = self.where_class()
where.add((Constraint(None, field.column, field), 'in',
pk_list[offset:offset + GET_ITERATOR_CHUNK_SIZE]), AND)
self.do_query(self.get_meta().db_table, where, using=using)
self.where = self.where_class()
self.add_q(Q(
**{field.attname + '__in': pk_list[offset:offset + GET_ITERATOR_CHUNK_SIZE]}))
self.do_query(self.get_meta().db_table, self.where, using=using)
def delete_qs(self, query, using):
"""
@ -80,9 +80,8 @@ class DeleteQuery(Query):
SelectInfo((self.get_initial_alias(), pk.column), None)
]
values = innerq
where = self.where_class()
where.add((Constraint(None, pk.column, pk), 'in', values), AND)
self.where = where
self.where = self.where_class()
self.add_q(Q(pk__in=values))
self.get_compiler(using).execute_sql(None)
@ -113,13 +112,10 @@ class UpdateQuery(Query):
related_updates=self.related_updates.copy(), **kwargs)
def update_batch(self, pk_list, values, using):
pk_field = self.get_meta().pk
self.add_update_values(values)
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
self.where = self.where_class()
self.where.add((Constraint(None, pk_field.column, pk_field), 'in',
pk_list[offset:offset + GET_ITERATOR_CHUNK_SIZE]),
AND)
self.add_q(Q(pk__in=pk_list[offset: offset + GET_ITERATOR_CHUNK_SIZE]))
self.get_compiler(using).execute_sql(None)
def add_update_values(self, values):

View File

@ -5,6 +5,7 @@ Code to manage the creation and SQL rendering of 'where' constraints.
import collections
import datetime
from itertools import repeat
import warnings
from django.conf import settings
from django.db.models.fields import DateTimeField, Field
@ -101,7 +102,7 @@ class WhereNode(tree.Node):
for child in self.children:
try:
if hasattr(child, 'as_sql'):
sql, params = child.as_sql(qn=qn, connection=connection)
sql, params = qn.compile(child)
else:
# A leaf node in the tree.
sql, params = self.make_atom(child, qn, connection)
@ -152,16 +153,16 @@ class WhereNode(tree.Node):
sql_string = '(%s)' % sql_string
return sql_string, result_params
def get_cols(self):
def get_group_by_cols(self):
cols = []
for child in self.children:
if hasattr(child, 'get_cols'):
cols.extend(child.get_cols())
if hasattr(child, 'get_group_by_cols'):
cols.extend(child.get_group_by_cols())
else:
if isinstance(child[0], Constraint):
cols.append((child[0].alias, child[0].col))
if hasattr(child[3], 'get_cols'):
cols.extend(child[3].get_cols())
if hasattr(child[3], 'get_group_by_cols'):
cols.extend(child[3].get_group_by_cols())
return cols
def make_atom(self, child, qn, connection):
@ -174,6 +175,9 @@ class WhereNode(tree.Node):
Returns the string for the SQL fragment and the parameters to use for
it.
"""
warnings.warn(
"The make_atom() method will be removed in Django 1.9. Use Lookup class instead.",
PendingDeprecationWarning)
lvalue, lookup_type, value_annotation, params_or_value = child
field_internal_type = lvalue.field.get_internal_type() if lvalue.field else None
@ -193,13 +197,13 @@ class WhereNode(tree.Node):
field_sql, field_params = self.sql_for_columns(lvalue, qn, connection, field_internal_type), []
else:
# A smart object with an as_sql() method.
field_sql, field_params = lvalue.as_sql(qn, connection)
field_sql, field_params = qn.compile(lvalue)
is_datetime_field = value_annotation is datetime.datetime
cast_sql = connection.ops.datetime_cast_sql() if is_datetime_field else '%s'
if hasattr(params, 'as_sql'):
extra, params = params.as_sql(qn, connection)
extra, params = qn.compile(params)
cast_sql = ''
else:
extra = ''
@ -282,6 +286,8 @@ class WhereNode(tree.Node):
if hasattr(child, 'relabel_aliases'):
# For example another WhereNode
child.relabel_aliases(change_map)
elif hasattr(child, 'relabeled_clone'):
self.children[pos] = child.relabeled_clone(change_map)
elif isinstance(child, (list, tuple)):
# tuple starting with Constraint
child = (child[0].relabeled_clone(change_map),) + child[1:]
@ -347,10 +353,13 @@ class Constraint(object):
pre-process itself prior to including in the WhereNode.
"""
def __init__(self, alias, col, field):
warnings.warn(
"The Constraint class will be removed in Django 1.9. Use Lookup class instead.",
PendingDeprecationWarning)
self.alias, self.col, self.field = alias, col, field
def prepare(self, lookup_type, value):
if self.field:
if self.field and not hasattr(value, 'as_sql'):
return self.field.get_prep_lookup(lookup_type, value)
return value

View File

@ -662,6 +662,12 @@ Django filter lookups: ``exact``, ``iexact``, ``contains``, ``icontains``,
``endswith``, ``iendswith``, ``range``, ``year``, ``month``, ``day``,
``isnull``, ``search``, ``regex``, and ``iregex``.
.. versionadded:: 1.7
If you are using :doc:`Custom lookups </ref/models/custom-lookups>` the
``lookup_type`` can be any ``lookup_name`` used by the project's custom
lookups.
Your method must be prepared to handle all of these ``lookup_type`` values and
should raise either a ``ValueError`` if the ``value`` is of the wrong sort (a
list when you were expecting an object, for example) or a ``TypeError`` if

View File

@ -81,7 +81,8 @@ manipulating the data of your Web application. Learn more about it below:
:doc:`Transactions <topics/db/transactions>` |
:doc:`Aggregation <topics/db/aggregation>` |
:doc:`Custom fields <howto/custom-model-fields>` |
:doc:`Multiple databases <topics/db/multi-db>`
:doc:`Multiple databases <topics/db/multi-db>` |
:doc:`Custom lookups <ref/models/custom-lookups>`
* **Other:**
:doc:`Supported databases <ref/databases>` |

View File

@ -0,0 +1,336 @@
==============
Custom lookups
==============
.. versionadded:: 1.7
.. module:: django.db.models.lookups
:synopsis: Custom lookups
.. currentmodule:: django.db.models
By default Django offers a wide variety of :ref:`built-in lookups
<field-lookups>` for filtering (for example, ``exact`` and ``icontains``). This
documentation explains how to write custom lookups and how to alter the working
of existing lookups.
A simple Lookup example
~~~~~~~~~~~~~~~~~~~~~~~
Let's start with a simple custom lookup. We will write a custom lookup ``ne``
which works opposite to ``exact``. ``Author.objects.filter(name__ne='Jack')``
will translate to the SQL::
"author"."name" <> 'Jack'
This SQL is backend independent, so we don't need to worry about different
databases.
There are two steps to making this work. Firstly we need to implement the
lookup, then we need to tell Django about it. The implementation is quite
straightforward::
from django.db.models import Lookup
class NotEqual(Lookup):
lookup_name = 'ne'
def as_sql(self, qn, connection):
lhs, lhs_params = self.process_lhs(qn, connection)
rhs, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params
return '%s <> %s' % (lhs, rhs), params
To register the ``NotEqual`` lookup we will just need to call
``register_lookup`` on the field class we want the lookup to be available. In
this case, the lookup makes sense on all ``Field`` subclasses, so we register
it with ``Field`` directly::
from django.db.models.fields import Field
Field.register_lookup(NotEqual)
We can now use ``foo__ne`` for any field ``foo``. You will need to ensure that
this registration happens before you try to create any querysets using it. You
could place the implementation in a ``models.py`` file, or register the lookup
in the ``ready()`` method of an ``AppConfig``.
Taking a closer look at the implementation, the first required attribute is
``lookup_name``. This allows the ORM to understand how to interpret ``name__ne``
and use ``NotEqual`` to generate the SQL. By convention, these names are always
lowercase strings containing only letters, but the only hard requirement is
that it must not contain the string ``__``.
A ``Lookup`` works against two values, ``lhs`` and ``rhs``, standing for
left-hand side and right-hand side. The left-hand side is usually a field
reference, but it can be anything implementing the :ref:`query expression API
<query-expression>`. The right-hand is the value given by the user. In the
example ``Author.objects.filter(name__ne='Jack')``, the left-hand side is a
reference to the ``name`` field of the ``Author`` model, and ``'Jack'`` is the
right-hand side.
We call ``process_lhs`` and ``process_rhs`` to convert them into the values we
need for SQL. In the above example, ``process_lhs`` returns
``('"author"."name"', [])`` and ``process_rhs`` returns ``('"%s"', ['Jack'])``.
In this example there were no parameters for the left hand side, but this would
depend on the object we have, so we still need to include them in the
parameters we return.
Finally we combine the parts into a SQL expression with ``<>``, and supply all
the parameters for the query. We then return a tuple containing the generated
SQL string and the parameters.
A simple transformer example
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The custom lookup above is great, but in some cases you may want to be able to
chain lookups together. For example, let's suppose we are building an
application where we want to make use of the ``abs()`` operator.
We have an ``Experiment`` model which records a start value, end value and the
change (start - end). We would like to find all experiments where the change
was equal to a certain amount (``Experiment.objects.filter(change__abs=27)``),
or where it did not exceede a certain amount
(``Experiment.objects.filter(change__abs__lt=27)``).
.. note::
This example is somewhat contrived, but it demonstrates nicely the range of
functionality which is possible in a database backend independent manner,
and without duplicating functionality already in Django.
We will start by writing a ``AbsoluteValue`` transformer. This will use the SQL
function ``ABS()`` to transform the value before comparison::
from django.db.models import Transform
class AbsoluteValue(Transform):
lookup_name = 'abs'
def as_sql(self, qn, connection):
lhs, params = qn.compile(self.lhs)
return "ABS(%s)" % lhs, params
Next, lets register it for ``IntegerField``::
from django.db.models import IntegerField
IntegerField.register_lookup(AbsoluteValue)
We can now run the queris we had before.
``Experiment.objects.filter(change__abs=27)`` will generate the following SQL::
SELECT ... WHERE ABS("experiments"."change") = 27
By using ``Transform`` instead of ``Lookup`` it means we are able to chain
further lookups afterwards. So
``Experiment.objects.filter(change__abs__lt=27)`` will generate the following
SQL::
SELECT ... WHERE ABS("experiments"."change") < 27
Subclasses of ``Transform`` usually only operate on the left-hand side of the
expression. Further lookups will work on the transformed value. Note that in
this case where there is no other lookup specified, Django interprets
``change__abs=27`` as ``change__abs__exact=27``.
When looking for which lookups are allowable after the ``Transform`` has been
applied, Django uses the ``output_type`` attribute. We didn't need to specify
this here as it didn't change, but supposing we were applying ``AbsoluteValue``
to some field which represents a more complex type (for example a point
relative to an origin, or a complex number) then we may have wanted to specify
``output_type = FloatField``, which will ensure that further lookups like
``abs__lte`` behave as they would for a ``FloatField``.
Writing an efficient abs__lt lookup
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When using the above written ``abs`` lookup, the SQL produced will not use
indexes efficiently in some cases. In particular, when we use
``change__abs__lt=27``, this is equivalent to ``change__gt=-27`` AND
``change__lt=27``. (For the ``lte`` case we could use the SQL ``BETWEEN``).
So we would like ``Experiment.objects.filter(change__abs__lt=27)`` to generate
the following SQL::
SELECT .. WHERE "experiments"."change" < 27 AND "experiments"."change" > -27
The implementation is::
from django.db.models import Lookup
class AbsoluteValueLessThan(Lookup):
lookup_name = 'lt'
def as_sql(self, qn, connection):
lhs, lhs_params = qn.compile(self.lhs.lhs)
rhs, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params + lhs_params + rhs_params
return '%s > %s AND %s < -%s % (lhs, rhs, lhs, rhs), params
AbsoluteValue.register_lookup(AbsoluteValueLessThan)
There are a couple of notable things going on. First, ``AbsoluteValueLessThan``
isn't calling ``process_lhs()``. Instead it skips the transformation of the
``lhs`` done by ``AbsoluteValue`` and uses the original ``lhs``. That is, we
want to get ``27`` not ``ABS(27)``. Referring directly to ``self.lhs.lhs`` is
safe as ``AbsoluteValueLessThan`` can be accessed only from the
``AbsoluteValue`` lookup, that is the ``lhs`` is always an instance of
``AbsoluteValue``.
Notice also that as both sides are used multiple times in the query the params
need to contain ``lhs_params`` and ``rhs_params`` multiple times.
The final query does the inversion (``27`` to ``-27``) directly in the
database. The reason for doing this is that if the self.rhs is something else
than a plain integer value (for example an ``F()`` reference) we can't do the
transformations in Python.
.. note::
In fact, most lookups with ``__abs`` could be implemented as range queries
like this, and on most database backend it is likely to be more sensible to
do so as you can make use of the indexes. However with PostgreSQL you may
want to add an index on ``abs(change)`` which would allow these queries to
be very efficient.
Writing alternative implemenatations for existing lookups
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sometimes different database vendors require different SQL for the same
operation. For this example we will rewrite a custom implementation for
MySQL for the NotEqual operator. Instead of ``<>`` we will be using ``!=``
operator. (Note that in reality almost all databases support both, including
all the official databases supported by Django).
We can change the behaviour on a specific backend by creating a subclass of
``NotEqual`` with a ``as_mysql`` method::
class MySQLNotEqual(NotEqual):
def as_mysql(self, qn, connection):
lhs, lhs_params = self.process_lhs(qn, connection)
rhs, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params
return '%s != %s' % (lhs, rhs), params
Field.register_lookup(MySQLNotExact)
We can then register it with ``Field``. It takes the place of the original
``NotEqual`` class as it has
When compiling a query, Django first looks for ``as_%s % connection.vendor``
methods, and then falls back to ``as_sql``. The vendor names for the in-built
backends are ``sqlite``, ``postgresql``, ``oracle`` and ``mysql``.
.. _query-expression:
The Query Expression API
~~~~~~~~~~~~~~~~~~~~~~~~
A lookup can assume that the lhs responds to the query expression API.
Currently direct field references, aggregates and ``Transform`` instances respond
to this API.
.. method:: as_sql(qn, connection)
Responsible for producing the query string and parameters for the
expression. The ``qn`` has a ``compile()`` method that can be used to
compile other expressions. The ``connection`` is the connection used to
execute the query.
Calling expression.as_sql() directly is usually incorrect - instead
qn.compile(expression) should be used. The qn.compile() method will take
care of calling vendor-specific methods of the expression.
.. method:: get_lookup(lookup_name)
The ``get_lookup()`` method is used to fetch lookups. By default the
lookup is fetched from the expression's output type in the same way
described in registering and fetching lookup documentation below.
It is possible to override this method to alter that behaviour.
.. method:: as_vendorname(qn, connection)
Works like ``as_sql()`` method. When an expression is compiled by
``qn.compile()``, Django will first try to call ``as_vendorname()``, where
vendorname is the vendor name of the backend used for executing the query.
The vendorname is one of ``postgresql``, ``oracle``, ``sqlite`` or
``mysql`` for Django's built-in backends.
.. attribute:: output_type
The ``output_type`` attribute is used by the ``get_lookup()`` method to check for
lookups. The output_type should be a field.
Note that this documentation lists only the public methods of the API.
Lookup reference
~~~~~~~~~~~~~~~~
.. class:: Lookup
In addition to the attributes and methods below, lookups also support
``as_sql`` and ``as_vendorname`` from the query expression API.
.. attribute:: lhs
The ``lhs`` (left-hand side) of a lookup tells us what we are comparing the
rhs to. It is an object which implements the query expression API. This is
likely to be a field, an aggregate or a subclass of ``Transform``.
.. attribute:: rhs
The ``rhs`` (right-hand side) of a lookup is the value we are comparing the
left hand side to. It may be a plain value, or something which compiles
into SQL, for example an ``F()`` object or a ``Queryset``.
.. attribute:: lookup_name
This class level attribute is used when registering lookups. It determines
the name used in queries to trigger this lookup. For example, ``contains``
or ``exact``. This should not contain the string ``__``.
.. method:: process_lhs(qn, connection)
This returns a tuple of ``(lhs_string, lhs_params)``. In some cases you may
wish to compile ``lhs`` directly in your ``as_sql`` methods using
``qn.compile(self.lhs)``.
.. method:: process_rhs(qn, connection)
Behaves the same as ``process_lhs`` but acts on the right-hand side.
Transform reference
~~~~~~~~~~~~~~~~~~~
.. class:: Transform
In addition to implementing the query expression API Transforms have the
following methods and attributes.
.. attribute:: lhs
The ``lhs`` (left-hand-side) of a transform contains the value to be
transformed. The ``lhs`` implements the query expression API.
.. attribute:: lookup_name
This class level attribute is used when registering lookups. It determines
the name used in queries to trigger this lookup. For example, ``year``
or ``dayofweek``. This should not contain the string ``__``.
.. _lookup-registration-api:
Registering and fetching lookups
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The lookup registration API is explained below.
.. classmethod:: register_lookup(lookup)
Registers the Lookup or Transform for the class. For example
``DateField.register_lookup(YearExact)`` will register ``YearExact`` for
all ``DateFields`` in the project, but also for fields that are instances
of a subclass of ``DateField`` (for example ``DateTimeField``).
.. method:: get_lookup(lookup_name)
Django uses ``get_lookup(lookup_name)`` to fetch lookups or transforms.
The implementation of ``get_lookup()`` fetches lookups or transforms
registered for the current class based on their lookup_name attribute.
The lookup registration API is available for ``Transform`` and ``Field`` classes.

View File

@ -343,6 +343,13 @@ underscores to spaces. See :ref:`Verbose field names <verbose-field-names>`.
A list of validators to run for this field. See the :doc:`validators
documentation </ref/validators>` for more information.
Registering and fetching lookups
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
``Field`` implements the :ref:`lookup registration API <lookup-registration-api>`.
The API can be used to customize which lookups are available for a field class, and
how lookups are fetched from a field.
.. _model-field-types:
Field types

View File

@ -13,3 +13,4 @@ Model API reference. For introductory material, see :doc:`/topics/db/models`.
instances
querysets
queries
custom-lookups

View File

@ -1995,6 +1995,9 @@ specified as keyword arguments to the ``QuerySet`` methods :meth:`filter()`,
For an introduction, see :ref:`models and database queries documentation
<field-lookups-intro>`.
Django's inbuilt lookups are listed below. It is also possible to write
:doc:`custom lookups </ref/models/custom-lookups>` for model fields.
.. fieldlookup:: exact
exact

View File

@ -180,6 +180,27 @@ for the following, instead of backend specific behavior.
finally:
c.close()
Custom lookups
~~~~~~~~~~~~~~
It is now possible to write custom lookups and transforms for the ORM.
Custom lookups work just like Django's inbuilt lookups (e.g. ``lte``,
``icontains``) while transforms are a new concept.
The :class:`django.db.models.Lookup` class provides a way to add lookup
operators for model fields. As an example it is possible to add ``day_lte``
opertor for ``DateFields``.
The :class:`django.db.models.Transform` class allows transformations of
database values prior to the final lookup. For example it is possible to
write a ``year`` transform that extracts year from the field's value.
Transforms allow for chaining. After the ``year`` transform has been added
to ``DateField`` it is possible to filter on the transformed value, for
example ``qs.filter(author__birthdate__year__lte=1981)``.
For more information about both custom lookups and transforms refer to
:doc:`custom lookups </ref/models/custom-lookups>` documentation.
Minor features
~~~~~~~~~~~~~~

View File

@ -443,7 +443,7 @@ class BaseAggregateTestCase(TestCase):
vals = Author.objects.filter(pk=1).aggregate(Count("friends__id"))
self.assertEqual(vals, {"friends__id__count": 2})
books = Book.objects.annotate(num_authors=Count("authors__name")).filter(num_authors__ge=2).order_by("pk")
books = Book.objects.annotate(num_authors=Count("authors__name")).filter(num_authors__exact=2).order_by("pk")
self.assertQuerysetEqual(
books, [
"The Definitive Guide to Django: Web Development Done Right",

View File

View File

@ -0,0 +1,13 @@
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
@python_2_unicode_compatible
class Author(models.Model):
name = models.CharField(max_length=20)
age = models.IntegerField(null=True)
birthdate = models.DateField(null=True)
average_rating = models.FloatField(null=True)
def __str__(self):
return self.name

View File

@ -0,0 +1,279 @@
from datetime import date
import unittest
from django.test import TestCase
from .models import Author
from django.db import models
from django.db import connection
class Div3Lookup(models.Lookup):
lookup_name = 'div3'
def as_sql(self, qn, connection):
lhs, params = self.process_lhs(qn, connection)
rhs, rhs_params = self.process_rhs(qn, connection)
params.extend(rhs_params)
return '%s %%%% 3 = %s' % (lhs, rhs), params
class Div3Transform(models.Transform):
lookup_name = 'div3'
def as_sql(self, qn, connection):
lhs, lhs_params = qn.compile(self.lhs)
return '%s %%%% 3' % (lhs,), lhs_params
class YearTransform(models.Transform):
lookup_name = 'year'
def as_sql(self, qn, connection):
lhs_sql, params = qn.compile(self.lhs)
return connection.ops.date_extract_sql('year', lhs_sql), params
@property
def output_type(self):
return models.IntegerField()
class YearExact(models.lookups.Lookup):
lookup_name = 'exact'
def as_sql(self, qn, connection):
# We will need to skip the extract part, and instead go
# directly with the originating field, that is self.lhs.lhs
lhs_sql, lhs_params = self.process_lhs(qn, connection, self.lhs.lhs)
rhs_sql, rhs_params = self.process_rhs(qn, connection)
# Note that we must be careful so that we have params in the
# same order as we have the parts in the SQL.
params = lhs_params + rhs_params + lhs_params + rhs_params
# We use PostgreSQL specific SQL here. Note that we must do the
# conversions in SQL instead of in Python to support F() references.
return ("%(lhs)s >= (%(rhs)s || '-01-01')::date "
"AND %(lhs)s <= (%(rhs)s || '-12-31')::date" %
{'lhs': lhs_sql, 'rhs': rhs_sql}, params)
YearTransform.register_lookup(YearExact)
class YearLte(models.lookups.LessThanOrEqual):
"""
The purpose of this lookup is to efficiently compare the year of the field.
"""
def as_sql(self, qn, connection):
# Skip the YearTransform above us (no possibility for efficient
# lookup otherwise).
real_lhs = self.lhs.lhs
lhs_sql, params = self.process_lhs(qn, connection, real_lhs)
rhs_sql, rhs_params = self.process_rhs(qn, connection)
params.extend(rhs_params)
# Build SQL where the integer year is concatenated with last month
# and day, then convert that to date. (We try to have SQL like:
# WHERE somecol <= '2013-12-31')
# but also make it work if the rhs_sql is field reference.
return "%s <= (%s || '-12-31')::date" % (lhs_sql, rhs_sql), params
YearTransform.register_lookup(YearLte)
# We will register this class temporarily in the test method.
class InMonth(models.lookups.Lookup):
"""
InMonth matches if the column's month is the same as value's month.
"""
lookup_name = 'inmonth'
def as_sql(self, qn, connection):
lhs, lhs_params = self.process_lhs(qn, connection)
rhs, rhs_params = self.process_rhs(qn, connection)
# We need to be careful so that we get the params in right
# places.
params = lhs_params + rhs_params + lhs_params + rhs_params
return ("%s >= date_trunc('month', %s) and "
"%s < date_trunc('month', %s) + interval '1 months'" %
(lhs, rhs, lhs, rhs), params)
class LookupTests(TestCase):
def test_basic_lookup(self):
a1 = Author.objects.create(name='a1', age=1)
a2 = Author.objects.create(name='a2', age=2)
a3 = Author.objects.create(name='a3', age=3)
a4 = Author.objects.create(name='a4', age=4)
models.IntegerField.register_lookup(Div3Lookup)
try:
self.assertQuerysetEqual(
Author.objects.filter(age__div3=0),
[a3], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(age__div3=1).order_by('age'),
[a1, a4], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(age__div3=2),
[a2], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(age__div3=3),
[], lambda x: x
)
finally:
models.IntegerField._unregister_lookup(Div3Lookup)
@unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific SQL used")
def test_birthdate_month(self):
a1 = Author.objects.create(name='a1', birthdate=date(1981, 2, 16))
a2 = Author.objects.create(name='a2', birthdate=date(2012, 2, 29))
a3 = Author.objects.create(name='a3', birthdate=date(2012, 1, 31))
a4 = Author.objects.create(name='a4', birthdate=date(2012, 3, 1))
models.DateField.register_lookup(InMonth)
try:
self.assertQuerysetEqual(
Author.objects.filter(birthdate__inmonth=date(2012, 1, 15)),
[a3], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(birthdate__inmonth=date(2012, 2, 1)),
[a2], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(birthdate__inmonth=date(1981, 2, 28)),
[a1], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(birthdate__inmonth=date(2012, 3, 12)),
[a4], lambda x: x
)
self.assertQuerysetEqual(
Author.objects.filter(birthdate__inmonth=date(2012, 4, 1)),
[], lambda x: x
)
finally:
models.DateField._unregister_lookup(InMonth)
def test_div3_extract(self):
models.IntegerField.register_lookup(Div3Transform)
try:
a1 = Author.objects.create(name='a1', age=1)
a2 = Author.objects.create(name='a2', age=2)
a3 = Author.objects.create(name='a3', age=3)
a4 = Author.objects.create(name='a4', age=4)
baseqs = Author.objects.order_by('name')
self.assertQuerysetEqual(
baseqs.filter(age__div3=2),
[a2], lambda x: x)
self.assertQuerysetEqual(
baseqs.filter(age__div3__lte=3),
[a1, a2, a3, a4], lambda x: x)
self.assertQuerysetEqual(
baseqs.filter(age__div3__in=[0, 2]),
[a2, a3], lambda x: x)
finally:
models.IntegerField._unregister_lookup(Div3Transform)
class YearLteTests(TestCase):
def setUp(self):
models.DateField.register_lookup(YearTransform)
self.a1 = Author.objects.create(name='a1', birthdate=date(1981, 2, 16))
self.a2 = Author.objects.create(name='a2', birthdate=date(2012, 2, 29))
self.a3 = Author.objects.create(name='a3', birthdate=date(2012, 1, 31))
self.a4 = Author.objects.create(name='a4', birthdate=date(2012, 3, 1))
def tearDown(self):
models.DateField._unregister_lookup(YearTransform)
@unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific SQL used")
def test_year_lte(self):
baseqs = Author.objects.order_by('name')
self.assertQuerysetEqual(
baseqs.filter(birthdate__year__lte=2012),
[self.a1, self.a2, self.a3, self.a4], lambda x: x)
self.assertQuerysetEqual(
baseqs.filter(birthdate__year=2012),
[self.a2, self.a3, self.a4], lambda x: x)
self.assertNotIn('BETWEEN', str(baseqs.filter(birthdate__year=2012).query))
self.assertQuerysetEqual(
baseqs.filter(birthdate__year__lte=2011),
[self.a1], lambda x: x)
# The non-optimized version works, too.
self.assertQuerysetEqual(
baseqs.filter(birthdate__year__lt=2012),
[self.a1], lambda x: x)
@unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific SQL used")
def test_year_lte_fexpr(self):
self.a2.age = 2011
self.a2.save()
self.a3.age = 2012
self.a3.save()
self.a4.age = 2013
self.a4.save()
baseqs = Author.objects.order_by('name')
self.assertQuerysetEqual(
baseqs.filter(birthdate__year__lte=models.F('age')),
[self.a3, self.a4], lambda x: x)
self.assertQuerysetEqual(
baseqs.filter(birthdate__year__lt=models.F('age')),
[self.a4], lambda x: x)
def test_year_lte_sql(self):
# This test will just check the generated SQL for __lte. This
# doesn't require running on PostgreSQL and spots the most likely
# error - not running YearLte SQL at all.
baseqs = Author.objects.order_by('name')
self.assertIn(
'<= (2011 || ', str(baseqs.filter(birthdate__year__lte=2011).query))
self.assertIn(
'-12-31', str(baseqs.filter(birthdate__year__lte=2011).query))
def test_postgres_year_exact(self):
baseqs = Author.objects.order_by('name')
self.assertIn(
'= (2011 || ', str(baseqs.filter(birthdate__year=2011).query))
self.assertIn(
'-12-31', str(baseqs.filter(birthdate__year=2011).query))
def test_custom_implementation_year_exact(self):
try:
# Two ways to add a customized implementation for different backends:
# First is MonkeyPatch of the class.
def as_custom_sql(self, qn, connection):
lhs_sql, lhs_params = self.process_lhs(qn, connection, self.lhs.lhs)
rhs_sql, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params + lhs_params + rhs_params
return ("%(lhs)s >= str_to_date(concat(%(rhs)s, '-01-01'), '%%%%Y-%%%%m-%%%%d') "
"AND %(lhs)s <= str_to_date(concat(%(rhs)s, '-12-31'), '%%%%Y-%%%%m-%%%%d')" %
{'lhs': lhs_sql, 'rhs': rhs_sql}, params)
setattr(YearExact, 'as_' + connection.vendor, as_custom_sql)
self.assertIn(
'concat(',
str(Author.objects.filter(birthdate__year=2012).query))
finally:
delattr(YearExact, 'as_' + connection.vendor)
try:
# The other way is to subclass the original lookup and register the subclassed
# lookup instead of the original.
class CustomYearExact(YearExact):
# This method should be named "as_mysql" for MySQL, "as_postgresql" for postgres
# and so on, but as we don't know which DB we are running on, we need to use
# setattr.
def as_custom_sql(self, qn, connection):
lhs_sql, lhs_params = self.process_lhs(qn, connection, self.lhs.lhs)
rhs_sql, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params + lhs_params + rhs_params
return ("%(lhs)s >= str_to_date(CONCAT(%(rhs)s, '-01-01'), '%%%%Y-%%%%m-%%%%d') "
"AND %(lhs)s <= str_to_date(CONCAT(%(rhs)s, '-12-31'), '%%%%Y-%%%%m-%%%%d')" %
{'lhs': lhs_sql, 'rhs': rhs_sql}, params)
setattr(CustomYearExact, 'as_' + connection.vendor, CustomYearExact.as_custom_sql)
YearTransform.register_lookup(CustomYearExact)
self.assertIn(
'CONCAT(',
str(Author.objects.filter(birthdate__year=2012).query))
finally:
YearTransform._unregister_lookup(CustomYearExact)
YearTransform.register_lookup(YearExact)

View File

@ -3,7 +3,7 @@ from __future__ import unicode_literals
from django.core.exceptions import FieldError
from django.db.models import F
from django.db import transaction
from django.test import TestCase
from django.test import TestCase, skipIfDBFeature
from django.utils import six
from .models import Company, Employee
@ -224,6 +224,25 @@ class ExpressionsTests(TestCase):
acme.num_employees = F("num_employees") + 16
self.assertRaises(TypeError, acme.save)
def test_ticket_11722_iexact_lookup(self):
Employee.objects.create(firstname="John", lastname="Doe")
Employee.objects.create(firstname="Test", lastname="test")
queryset = Employee.objects.filter(firstname__iexact=F('lastname'))
self.assertQuerysetEqual(queryset, ["<Employee: Test test>"])
@skipIfDBFeature('has_case_insensitive_like')
def test_ticket_16731_startswith_lookup(self):
Employee.objects.create(firstname="John", lastname="Doe")
e2 = Employee.objects.create(firstname="Jack", lastname="Jackson")
e3 = Employee.objects.create(firstname="Jack", lastname="jackson")
self.assertQuerysetEqual(
Employee.objects.filter(lastname__startswith=F('firstname')),
[e2], lambda x: x)
self.assertQuerysetEqual(
Employee.objects.filter(lastname__istartswith=F('firstname')).order_by('pk'),
[e2, e3], lambda x: x)
def test_ticket_18375_join_reuse(self):
# Test that reverse multijoin F() references and the lookup target
# the same join. Pre #18375 the F() join was generated first, and the

View File

@ -45,9 +45,6 @@ class NullQueriesTests(TestCase):
# Can't use None on anything other than __exact and __iexact
self.assertRaises(ValueError, Choice.objects.filter, id__gt=None)
# Can't use None on anything other than __exact and __iexact
self.assertRaises(ValueError, Choice.objects.filter, foo__gt=None)
# Related managers use __exact=None implicitly if the object hasn't been saved.
p2 = Poll(question="How?")
self.assertEqual(repr(p2.choice_set.all()), '[]')

View File

@ -2632,8 +2632,15 @@ class WhereNodeTest(TestCase):
def as_sql(self, qn, connection):
return 'dummy', []
class MockCompiler(object):
def compile(self, node):
return node.as_sql(self, connection)
def __call__(self, name):
return connection.ops.quote_name(name)
def test_empty_full_handling_conjunction(self):
qn = connection.ops.quote_name
qn = WhereNodeTest.MockCompiler()
w = WhereNode(children=[EverythingNode()])
self.assertEqual(w.as_sql(qn, connection), ('', []))
w.negate()
@ -2658,7 +2665,7 @@ class WhereNodeTest(TestCase):
self.assertEqual(w.as_sql(qn, connection), ('', []))
def test_empty_full_handling_disjunction(self):
qn = connection.ops.quote_name
qn = WhereNodeTest.MockCompiler()
w = WhereNode(children=[EverythingNode()], connector='OR')
self.assertEqual(w.as_sql(qn, connection), ('', []))
w.negate()
@ -2685,7 +2692,7 @@ class WhereNodeTest(TestCase):
self.assertEqual(w.as_sql(qn, connection), ('NOT (dummy)', []))
def test_empty_nodes(self):
qn = connection.ops.quote_name
qn = WhereNodeTest.MockCompiler()
empty_w = WhereNode()
w = WhereNode(children=[empty_w, empty_w])
self.assertEqual(w.as_sql(qn, connection), (None, []))