Ticket #6095: 6095-alpha-03.diff

File 6095-alpha-03.diff, 15.1 KB (added by floguy, 7 years ago)
  • django/db/models/fields/related.py

     
    11from django.db import connection, transaction
    2 from django.db.models import signals, get_model
     2from django.db.models import signals, get_model, get_models
    33from django.db.models.fields import AutoField, Field, IntegerField, PositiveIntegerField, PositiveSmallIntegerField, get_ul_class
    44from django.db.models.related import RelatedObject
    55from django.utils.text import capfirst
    66from django.utils.translation import ugettext_lazy, string_concat, ungettext, ugettext as _
    7 from django.utils.functional import curry
     7from django.utils.functional import curry, memoize
    88from django.utils.encoding import smart_unicode
    99from django.core import validators
    1010from django import oldforms
     
    2323
    2424pending_lookups = {}
    2525
     26memoized_fk_field_reversals = {}
     27
     28model_db_table_cache = {}
     29
    2630def add_lookup(rel_cls, field):
    2731    name = field.rel.to
    2832    module = rel_cls.__module__
     
    5458    except klass.DoesNotExist:
    5559        raise validators.ValidationError, _("Please enter a valid %s.") % f.verbose_name
    5660
     61def get_reverse_rel_field(from_model, to_model, related_name):
     62    key = (from_model._meta.app_label, from_model._meta.object_name,
     63            to_model._meta.app_label, to_model._meta.object_name,
     64            related_name)
     65    try:
     66        found_field = memoized_fk_field_reversals[key]
     67    except KeyError:
     68        found_field = None
     69        for field in from_model._meta.fields:
     70            if field.__class__ in (ForeignKey, OneToOneField, ManyToManyField):
     71                if field.rel.to == to_model:
     72                    found_field = field
     73                    break
     74        memoized_fk_field_reversals[key] = found_field
     75    return found_field
     76
     77def get_model_for_db_table(db_table):
     78    for model in get_models():
     79        if model._meta.db_table == db_table:
     80            return model
     81    return None
     82get_model_for_db_table = memoize(get_model_for_db_table, model_db_table_cache, 1)
     83
    5784#HACK
    5885class RelatedField(object):
    5986    def contribute_to_class(self, cls, name):
     
    267294    and adds behavior for many-to-many related objects."""
    268295    class ManyRelatedManager(superclass):
    269296        def __init__(self, model=None, core_filters=None, instance=None, symmetrical=None,
    270                 join_table=None, source_col_name=None, target_col_name=None):
     297                join_table=None, source_col_name=None, source_attname=None,
     298                target_attname=None, target_col_name=None):
    271299            super(ManyRelatedManager, self).__init__()
    272300            self.core_filters = core_filters
    273301            self.model = model
     
    276304            self.join_table = join_table
    277305            self.source_col_name = source_col_name
    278306            self.target_col_name = target_col_name
     307            self.source_attname = source_attname
     308            self.target_attname = target_attname
     309            self.intermediary_model = get_model_for_db_table(self.join_table.replace('"',''))
    279310            self._pk_val = self.instance._get_pk_val()
    280311            if self._pk_val is None:
    281312                raise ValueError("%r instance needs to have a primary key value before a many-to-many relationship can be used." % model)
     
    340371
    341372                # Add the ones that aren't there already
    342373                for obj_id in (new_ids - existing_ids):
    343                     cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
     374                    if self.intermediary_model == None:
     375                        cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
    344376                        (self.join_table, source_col_name, target_col_name),
    345377                        [self._pk_val, obj_id])
     378                    else:
     379                        new_obj = self.intermediary_model()
     380                        setattr(new_obj, self.source_attname, self._pk_val)
     381                        setattr(new_obj, self.target_attname, obj_id)
     382                        new_obj.save()
    346383                transaction.commit_unless_managed()
    347384
    348385        def _remove_items(self, source_col_name, target_col_name, *objs):
     
    398435        RelatedManager = create_many_related_manager(superclass)
    399436
    400437        qn = connection.ops.quote_name
     438        rel_field = self.related.field
    401439        manager = RelatedManager(
    402440            model=rel_model,
    403441            core_filters={'%s__pk' % self.related.field.name: instance._get_pk_val()},
    404442            instance=instance,
    405443            symmetrical=False,
    406             join_table=qn(self.related.field.m2m_db_table()),
    407             source_col_name=qn(self.related.field.m2m_reverse_name()),
    408             target_col_name=qn(self.related.field.m2m_column_name())
     444            join_table=qn(rel_field.m2m_db_table()),
     445            source_col_name=qn(rel_field.m2m_reverse_name()),
     446            target_col_name=qn(rel_field.m2m_column_name()),
     447            source_attname=rel_field.m2m_reverse_attname(),
     448            target_attname=rel_field.m2m_attname()
    409449        )
    410450
    411451        return manager
     
    446486            symmetrical=(self.field.rel.symmetrical and instance.__class__ == rel_model),
    447487            join_table=qn(self.field.m2m_db_table()),
    448488            source_col_name=qn(self.field.m2m_column_name()),
    449             target_col_name=qn(self.field.m2m_reverse_name())
     489            target_col_name=qn(self.field.m2m_reverse_name()),
     490            source_attname=self.field.m2m_attname(),
     491            target_attname=self.field.m2m_reverse_attname()
    450492        )
    451493
    452494        return manager
     
    648690            filter_interface=kwargs.pop('filter_interface', None),
    649691            limit_choices_to=kwargs.pop('limit_choices_to', None),
    650692            raw_id_admin=kwargs.pop('raw_id_admin', False),
    651             symmetrical=kwargs.pop('symmetrical', True))
     693            symmetrical=kwargs.pop('symmetrical', True),
     694            through=kwargs.pop('through', None))
    652695        self.db_table = kwargs.pop('db_table', None)
     696        if kwargs['rel'].through:
     697            assert not self.db_table, "Cannot specify a db_table if an intermediary model is used."
    653698        if kwargs["rel"].raw_id_admin:
    654699            kwargs.setdefault("validator_list", []).append(self.isValidIDList)
    655700        Field.__init__(self, **kwargs)
     
    672717
    673718    def _get_m2m_db_table(self, opts):
    674719        "Function that can be curried to provide the m2m table name for this relation"
    675         if self.db_table:
     720        if self.rel.through != None:
     721            return get_model(opts.app_label, self.rel.through)._meta.db_table
     722        elif self.db_table:
    676723            return self.db_table
    677724        else:
    678725            return '%s_%s' % (opts.db_table, self.name)
    679726
     727    def _get_m2m_attname(self, related):
     728        try:
     729            through = get_model(related.opts.app_label, self.rel.through)
     730            field = get_reverse_rel_field(through, related.model, self.rel.related_name)
     731            attname, column = field.get_attname_column()
     732            return attname
     733        except:
     734            return None
     735
    680736    def _get_m2m_column_name(self, related):
    681737        "Function that can be curried to provide the source column name for the m2m table"
    682738        # If this is an m2m relation to self, avoid the inevitable name clash
    683         if related.model == related.parent_model:
     739        if self.rel.through != None:
     740            through = get_model(related.opts.app_label, self.rel.through)
     741            field = get_reverse_rel_field(through, related.model, self.rel.related_name)
     742            attname, column = field.get_attname_column()
     743            return column
     744        elif related.model == related.parent_model:
    684745            return 'from_' + related.model._meta.object_name.lower() + '_id'
    685746        else:
    686747            return related.model._meta.object_name.lower() + '_id'
    687748
     749    def _get_m2m_reverse_attname(self, related):
     750        try:
     751            through = get_model(related.opts.app_label, self.rel.through)
     752            field = get_reverse_rel_field(through, related.parent_model, self.rel.related_name)
     753            attname, column = field.get_attname_column()
     754            return attname
     755        except:
     756            return None
     757
    688758    def _get_m2m_reverse_name(self, related):
    689759        "Function that can be curried to provide the related column name for the m2m table"
    690760        # If this is an m2m relation to self, avoid the inevitable name clash
    691         if related.model == related.parent_model:
     761        if self.rel.through != None:
     762            through = get_model(related.opts.app_label, self.rel.through)
     763            field = get_reverse_rel_field(through, related.parent_model, self.rel.related_name)
     764            attname, column = field.get_attname_column()
     765            return column
     766        elif related.model == related.parent_model:
    692767            return 'to_' + related.parent_model._meta.object_name.lower() + '_id'
    693768        else:
    694769            return related.parent_model._meta.object_name.lower() + '_id'
     
    745820        # Set up the accessors for the column names on the m2m table
    746821        self.m2m_column_name = curry(self._get_m2m_column_name, related)
    747822        self.m2m_reverse_name = curry(self._get_m2m_reverse_name, related)
     823        self.m2m_attname = curry(self._get_m2m_attname, related)
     824        self.m2m_reverse_attname = curry(self._get_m2m_reverse_attname, related)
    748825
    749826    def set_attributes_from_rel(self):
    750827        pass
     
    809886
    810887class ManyToManyRel(object):
    811888    def __init__(self, to, num_in_admin=0, related_name=None,
    812         filter_interface=None, limit_choices_to=None, raw_id_admin=False, symmetrical=True):
     889        filter_interface=None, limit_choices_to=None, raw_id_admin=False, symmetrical=True,
     890        through = None):
    813891        self.to = to
    814892        self.num_in_admin = num_in_admin
    815893        self.related_name = related_name
     
    821899        self.raw_id_admin = raw_id_admin
    822900        self.symmetrical = symmetrical
    823901        self.multiple = True
     902        self.through = through
    824903
    825904        assert not (self.raw_id_admin and self.filter_interface), "ManyToManyRels may not use both raw_id_admin and filter_interface"
  • django/core/management/sql.py

     
    349349    qn = connection.ops.quote_name
    350350    inline_references = connection.features.inline_fk_references
    351351    for f in opts.many_to_many:
    352         if not isinstance(f.rel, generic.GenericRel):
     352        if not isinstance(f.rel, generic.GenericRel) and getattr(f.rel, 'through', None) == None:
    353353            tablespace = f.db_tablespace or opts.db_tablespace
    354354            if tablespace and connection.features.supports_tablespaces and connection.features.autoindexes_primary_keys:
    355355                tablespace_sql = ' ' + connection.ops.tablespace_sql(tablespace, inline=True)
  • tests/modeltests/m2m_manual/models.py

     
     1from django.db import models
     2from datetime import datetime
     3
     4# M2M described on one of the models
     5class Person(models.Model):
     6    name = models.CharField(max_length=128)
     7
     8    def __unicode__(self):
     9        return self.name
     10
     11class Group(models.Model):
     12    name = models.CharField(max_length=128)
     13    members = models.ManyToManyField(Person, through='Membership')
     14    custom_members = models.ManyToManyField(Person, through='CustomMembership', related_name="custom")
     15   
     16    def __unicode__(self):
     17        return self.name
     18
     19class Membership(models.Model):
     20    person = models.ForeignKey(Person)
     21    group = models.ForeignKey(Group)
     22    date_joined = models.DateTimeField(default=datetime.now)
     23    invite_reason = models.CharField(max_length=64, null=True, blank=True)
     24   
     25    def __unicode__(self):
     26        return "%s is a member of %s" % (self.person.name, self.group.name)
     27
     28class CustomMembership(models.Model):
     29    person = models.ForeignKey(Person, db_column="custom_person_column", related_name="custom_person_related_name")
     30    group = models.ForeignKey(Group)
     31    date_joined = models.DateTimeField(default=datetime.now)
     32   
     33    def __unicode__(self):
     34        return "%s is a member of %s" % (self.person.name, self.group.name)
     35
     36__test__ = {'API_TESTS':"""
     37>>> from datetime import datetime
     38
     39>>> bob = Person(name = 'Bob')
     40>>> bob.save()
     41>>> jim = Person(name = 'Jim')
     42>>> jim.save()
     43>>> jane = Person(name = 'Jane')
     44>>> jane.save()
     45>>> rock = Group(name = 'Rock')
     46>>> rock.save()
     47>>> roll = Group(name = 'Roll')
     48>>> roll.save()
     49
     50>>> rock.members.add(jim, jane)
     51>>> rock.members.all()
     52[<Person: Jim>, <Person: Jane>]
     53
     54>>> roll.members.add(bob, jim)
     55>>> roll.members.all()
     56[<Person: Bob>, <Person: Jim>]
     57
     58>>> jane.group_set.all()
     59[<Group: Rock>]
     60
     61>>> jane.group_set.add(roll)
     62>>> jane.group_set.all()
     63[<Group: Rock>, <Group: Roll>]
     64
     65>>> jim.group_set.all()
     66[<Group: Rock>, <Group: Roll>]
     67
     68# Check to make sure that the associated Membership object is created.
     69>>> m = Membership.objects.get(person = jane, group = rock)
     70>>> m
     71<Membership: Jane is a member of Rock>
     72
     73>>> m.invite_reason = "She was just so awesome."
     74>>> m.save()
     75
     76>>> Membership.objects.filter(person = jim)
     77[<Membership: Jim is a member of Rock>, <Membership: Jim is a member of Roll>]
     78
     79>>> rock.custom_members.add(bob)
     80>>> rock.custom_members.all()
     81[<Person: Bob>]
     82
     83>>> jim.custom.add(rock)
     84>>> rock.custom_members.all()
     85[<Person: Bob>, <Person: Jim>]
     86
     87>>> jim.custom.all()
     88[<Group: Rock>]
     89
     90>>> jim.custom_person_related_name.all()
     91[<CustomMembership: Jim is a member of Rock>]
     92
     93###QUERY TESTS###
     94# Queries involving the related model (Person, in the case of Group) use its attname
     95>>> Group.objects.filter(members__name='Bob')
     96[<Group: Roll>]
     97
     98# Queries involving the relationship model (Membership, in the case of Group) use its model name
     99>>> Group.objects.filter(membership__invite_reason = "She was just so awesome.")
     100[<Group: Rock>]
     101
     102# Queries involving the reverse related model (Group, in the case of Person) use its model name
     103>>> Person.objects.filter(group__name="Rock")
     104[<Person: Jim>, <Person: Jane>]
     105
     106# If the m2m field has specified a related_name, using that will work.
     107>>> Person.objects.filter(custom__name="Rock")
     108[<Person: Bob>, <Person: Jim>]
     109
     110# Queries involving the relationship model (Membership, in the case of Group) use its model name
     111>>> Person.objects.filter(membership__invite_reason = "She was just so awesome.")
     112[<Person: Jane>]
     113
     114# Sometimes these queries can return non-distinct resultsets.
     115>>> Person.objects.filter(membership__date_joined__day = datetime.now().day)
     116[<Person: Bob>, <Person: Jim>, <Person: Jim>, <Person: Jane>, <Person: Jane>]
     117
     118# Adding a .distinct() works to correct this.
     119>>> Person.objects.filter(membership__date_joined__day = datetime.now().day).distinct()
     120[<Person: Bob>, <Person: Jim>, <Person: Jane>]
     121"""}
     122 No newline at end of file
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