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[multi-db] Added optional db_connection property to model Meta classes,
which can be used to set the name of the connection for the model. Updated query generation in model, query and fields/related to use the model's connection and backend. Added basic model connection access to multiple db test. git-svn-id: http://code.djangoproject.com/svn/django/branches/multiple-db-support@3234 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Jason Pellerin
parent
9bae64fa76
commit
75b64abaa7
@ -7,7 +7,7 @@ from django.db.models.fields.related import OneToOneRel, ManyToOneRel
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from django.db.models.related import RelatedObject
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from django.db.models.query import orderlist2sql, delete_objects
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from django.db.models.options import Options, AdminOptions
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from django.db import connection, backend, transaction
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from django.db import transaction
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from django.db.models import signals
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from django.db.models.loading import register_models, get_model
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from django.dispatch import dispatcher
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@ -158,6 +158,9 @@ class Model(object):
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def save(self):
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dispatcher.send(signal=signals.pre_save, sender=self.__class__, instance=self)
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info = self._meta.connection_info
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connection = info.connection
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backend = info.backend
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non_pks = [f for f in self._meta.fields if not f.primary_key]
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cursor = connection.cursor()
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@ -205,7 +208,7 @@ class Model(object):
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backend.get_pk_default_value()))
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if self._meta.has_auto_field and not pk_set:
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setattr(self, self._meta.pk.attname, backend.get_last_insert_id(cursor, self._meta.db_table, self._meta.pk.column))
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transaction.commit_unless_managed()
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transaction.commit_unless_managed([connection])
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# Run any post-save hooks.
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dispatcher.send(signal=signals.post_save, sender=self.__class__, instance=self)
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@ -276,6 +279,7 @@ class Model(object):
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return dict(field.choices).get(value, value)
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def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
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backend = self._meta.connection_info.backend
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op = is_next and '>' or '<'
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where = '(%s %s %%s OR (%s = %%s AND %s.%s %s %%s))' % \
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(backend.quote_name(field.column), op, backend.quote_name(field.column),
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@ -290,6 +294,7 @@ class Model(object):
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raise self.DoesNotExist, "%s matching query does not exist." % self.__class__._meta.object_name
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def _get_next_or_previous_in_order(self, is_next):
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backend = self._meta.connection_info.backend
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cachename = "__%s_order_cache" % is_next
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if not hasattr(self, cachename):
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op = is_next and '>' or '<'
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@ -378,6 +383,9 @@ class Model(object):
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rel = rel_field.rel.to
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m2m_table = rel_field.m2m_db_table()
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this_id = self._get_pk_val()
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info = self._meta.connection_info
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connection = info.connection
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backend = info.backend
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cursor = connection.cursor()
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cursor.execute("DELETE FROM %s WHERE %s = %%s" % \
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(backend.quote_name(m2m_table),
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@ -387,7 +395,7 @@ class Model(object):
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backend.quote_name(rel_field.m2m_column_name()),
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backend.quote_name(rel_field.m2m_reverse_name()))
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cursor.executemany(sql, [(this_id, i) for i in id_list])
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transaction.commit_unless_managed()
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transaction.commit_unless_managed([connection])
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############################################
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# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
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@ -396,6 +404,9 @@ class Model(object):
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# ORDERING METHODS #########################
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def method_set_order(ordered_obj, self, id_list):
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connection_info = ordered_obj._meta.connection_info
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connection = info.connection
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backend = info.backend
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cursor = connection.cursor()
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# Example: "UPDATE poll_choices SET _order = %s WHERE poll_id = %s AND id = %s"
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sql = "UPDATE %s SET %s = %%s WHERE %s = %%s AND %s = %%s" % \
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@ -404,9 +415,12 @@ def method_set_order(ordered_obj, self, id_list):
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backend.quote_name(ordered_obj._meta.pk.column))
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rel_val = getattr(self, ordered_obj._meta.order_with_respect_to.rel.field_name)
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cursor.executemany(sql, [(i, rel_val, j) for i, j in enumerate(id_list)])
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transaction.commit_unless_managed()
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transaction.commit_unless_managed([connection])
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def method_get_order(ordered_obj, self):
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connection_info = ordered_obj.connection_info
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connection = info.connection
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backend = info.backend
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cursor = connection.cursor()
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# Example: "SELECT id FROM poll_choices WHERE poll_id = %s ORDER BY _order"
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sql = "SELECT %s FROM %s WHERE %s = %%s ORDER BY %s" % \
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@ -1,4 +1,4 @@
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from django.db import backend, connection, transaction
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from django.db import transaction
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from django.db.models import signals, get_model
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from django.db.models.fields import AutoField, Field, IntegerField, get_ul_class
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from django.db.models.related import RelatedObject
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@ -290,7 +290,7 @@ def create_many_related_manager(superclass):
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# source_col_name: the PK colname in join_table for the source object
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# target_col_name: the PK colname in join_table for the target object
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# *objs - objects to add
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from django.db import connection
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connection = self.model._meta.connection
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# Add the newly created or already existing objects to the join table.
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# First find out which items are already added, to avoid adding them twice
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@ -310,13 +310,13 @@ def create_many_related_manager(superclass):
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cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
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(self.join_table, source_col_name, target_col_name),
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[self._pk_val, obj_id])
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transaction.commit_unless_managed()
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transaction.commit_unless_managed(connection)
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def _remove_items(self, source_col_name, target_col_name, *objs):
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# source_col_name: the PK colname in join_table for the source object
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# target_col_name: the PK colname in join_table for the target object
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# *objs - objects to remove
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from django.db import connection
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connection = self.model._meta.connection
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for obj in objs:
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if not isinstance(obj, self.model):
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@ -327,16 +327,16 @@ def create_many_related_manager(superclass):
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cursor.execute("DELETE FROM %s WHERE %s = %%s AND %s = %%s" % \
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(self.join_table, source_col_name, target_col_name),
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[self._pk_val, obj._get_pk_val()])
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transaction.commit_unless_managed()
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transaction.commit_unless_managed(connection)
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def _clear_items(self, source_col_name):
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# source_col_name: the PK colname in join_table for the source object
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from django.db import connection
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connection = self.model._meta.connection
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cursor = connection.cursor()
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cursor.execute("DELETE FROM %s WHERE %s = %%s" % \
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(self.join_table, source_col_name),
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[self._pk_val])
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transaction.commit_unless_managed()
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transaction.commit_unless_managed(connection)
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return ManyRelatedManager
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@ -360,6 +360,7 @@ class ManyRelatedObjectsDescriptor(object):
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superclass = rel_model._default_manager.__class__
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RelatedManager = create_many_related_manager(superclass)
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backend = rel_model._meta.connection_info.backend
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qn = backend.quote_name
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manager = RelatedManager(
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model=rel_model,
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@ -402,6 +403,7 @@ class ReverseManyRelatedObjectsDescriptor(object):
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superclass = rel_model._default_manager.__class__
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RelatedManager = create_many_related_manager(superclass)
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backend = rel_model._meta.connection_info.backend
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qn = backend.quote_name
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manager = RelatedManager(
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model=rel_model,
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@ -1,4 +1,5 @@
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from django.conf import settings
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from django.db import connection_info, connections
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from django.db.models.related import RelatedObject
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from django.db.models.fields.related import ManyToManyRel
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from django.db.models.fields import AutoField, FieldDoesNotExist
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@ -11,7 +12,7 @@ import re
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# Calculate the verbose_name by converting from InitialCaps to "lowercase with spaces".
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get_verbose_name = lambda class_name: re.sub('(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|$)))', ' \\1', class_name).lower().strip()
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DEFAULT_NAMES = ('verbose_name', 'db_table', 'ordering',
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DEFAULT_NAMES = ('verbose_name', 'db_connection', 'db_table', 'ordering',
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'unique_together', 'permissions', 'get_latest_by',
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'order_with_respect_to', 'app_label')
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@ -20,6 +21,7 @@ class Options(object):
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self.fields, self.many_to_many = [], []
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self.module_name, self.verbose_name = None, None
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self.verbose_name_plural = None
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self.db_connection = None
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self.db_table = ''
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self.ordering = []
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self.unique_together = []
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@ -90,6 +92,17 @@ class Options(object):
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def __str__(self):
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return "%s.%s" % (self.app_label, self.module_name)
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def get_connection_info(self):
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if self.db_connection:
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return connections[self.db_connection]
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return connection_info
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connection_info = property(get_connection_info)
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def get_connection(self):
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"""Get the database connection for this object's model"""
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return self.get_connection_info().connection
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connection = property(get_connection)
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def get_field(self, name, many_to_many=True):
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"Returns the requested field by name. Raises FieldDoesNotExist on error."
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@ -1,4 +1,4 @@
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from django.db import backend, connection, transaction
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from django.db import transaction
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from django.db.models.fields import DateField, FieldDoesNotExist
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from django.db.models import signals
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from django.dispatch import dispatcher
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@ -157,8 +157,7 @@ class QuerySet(object):
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# self._select is a dictionary, and dictionaries' key order is
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# undefined, so we convert it to a list of tuples.
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extra_select = self._select.items()
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cursor = connection.cursor()
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cursor = self.model._meta.connection.cursor()
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select, sql, params = self._get_sql_clause()
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cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
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fill_cache = self._select_related
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@ -178,6 +177,9 @@ class QuerySet(object):
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def count(self):
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"Performs a SELECT COUNT() and returns the number of records as an integer."
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info = self.model._meta.connection_info
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backend = info.backend
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connection = info.connection
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counter = self._clone()
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counter._order_by = ()
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counter._offset = None
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@ -247,6 +249,7 @@ class QuerySet(object):
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Returns a dictionary mapping each of the given IDs to the object with
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that ID.
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"""
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backend = self.model._meta.connection_info.backend
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assert self._limit is None and self._offset is None, \
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"Cannot use 'limit' or 'offset' with in_bulk"
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assert isinstance(id_list, (tuple, list)), "in_bulk() must be provided with a list of IDs."
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@ -423,7 +426,7 @@ class QuerySet(object):
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def _get_sql_clause(self):
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opts = self.model._meta
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backend = opts.connection_info.backend
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# Construct the fundamental parts of the query: SELECT X FROM Y WHERE Z.
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select = ["%s.%s" % (backend.quote_name(opts.db_table), backend.quote_name(f.column)) for f in opts.fields]
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tables = [quote_only_if_word(t) for t in self._tables]
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@ -514,6 +517,9 @@ class ValuesQuerySet(QuerySet):
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columns = [f.column for f in self.model._meta.fields]
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field_names = [f.attname for f in self.model._meta.fields]
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info = self.model._meta.connection_info
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backend = info.backend
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connection = info.connection
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cursor = connection.cursor()
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select, sql, params = self._get_sql_clause()
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select = ['%s.%s' % (backend.quote_name(self.model._meta.db_table), backend.quote_name(c)) for c in columns]
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@ -533,6 +539,10 @@ class ValuesQuerySet(QuerySet):
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class DateQuerySet(QuerySet):
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def iterator(self):
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from django.db.backends.util import typecast_timestamp
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info = self.model._meta.connection_info
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backend = info.backend
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connection = info.connection
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self._order_by = () # Clear this because it'll mess things up otherwise.
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if self._field.null:
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self._where.append('%s.%s IS NOT NULL' % \
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@ -625,7 +635,9 @@ class QNot(Q):
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where2 = ['(NOT (%s))' % " AND ".join(where)]
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return tables, joins, where2, params
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def get_where_clause(lookup_type, table_prefix, field_name, value):
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def get_where_clause(opts, lookup_type, table_prefix, field_name, value):
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backend = opts.connection_info.backend
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if table_prefix.endswith('.'):
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table_prefix = backend.quote_name(table_prefix[:-1])+'.'
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field_name = backend.quote_name(field_name)
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@ -660,6 +672,7 @@ def fill_table_cache(opts, select, tables, where, old_prefix, cache_tables_seen)
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Helper function that recursively populates the select, tables and where (in
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place) for fill-cache queries.
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"""
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backend = opts.connection_info.backend
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for f in opts.fields:
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if f.rel and not f.null:
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db_table = f.rel.to._meta.db_table
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@ -753,6 +766,9 @@ def lookup_inner(path, clause, value, opts, table, column):
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current_column = column
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intermediate_table = None
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join_required = False
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info = current_opts.connection_info
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backend = info.backend
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connection = info.connection
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name = path.pop(0)
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# Has the primary key been requested? If so, expand it out
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@ -881,7 +897,7 @@ def lookup_inner(path, clause, value, opts, table, column):
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else:
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column = field.column
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where.append(get_where_clause(clause, current_table + '.', column, value))
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where.append(get_where_clause(current_opts, clause, current_table + '.', column, value))
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params.extend(field.get_db_prep_lookup(clause, value))
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return tables, joins, where, params
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@ -891,9 +907,12 @@ def delete_objects(seen_objs):
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ordered_classes = seen_objs.keys()
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ordered_classes.reverse()
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cursor = connection.cursor()
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for cls in ordered_classes:
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info = cls._meta.connection_info
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backend = info.backend
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connection = info.connection
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cursor = connection.cursor()
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seen_objs[cls] = seen_objs[cls].items()
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seen_objs[cls].sort()
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@ -927,7 +946,16 @@ def delete_objects(seen_objs):
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pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
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# Now delete the actual data
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dirty_conns = []
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for cls in ordered_classes:
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info = cls._meta.connection_info
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backend = info.backend
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connection = info.connection
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cursor = connection.cursor()
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if connection not in dirty_conns:
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dirty_conns.append(connection)
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seen_objs[cls].reverse()
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pk_list = [pk for pk,instance in seen_objs[cls]]
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for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
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@ -947,4 +975,4 @@ def delete_objects(seen_objs):
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setattr(instance, cls._meta.pk.attname, None)
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dispatcher.send(signal=signals.post_delete, sender=cls, instance=instance)
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transaction.commit_unless_managed()
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transaction.commit_unless_managed(dirty_conns)
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@ -50,7 +50,7 @@ with the attributes: `DatabaseError`, `backend`,
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`runshell`. Access connections through the `connections` property of
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the `django.db` module:
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>>> from django.db import connections
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>>> from django.db import connection, connections
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>>> connections['a'].settings.DATABASE_NAME == db_a
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True
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>>> connections['b'].settings.DATABASE_NAME == db_b
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@ -62,6 +62,65 @@ Invalid connection names raise ImproperlyConfigured:
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Traceback (most recent call last):
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...
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ImproperlyConfigured: No database connection 'bad' has been configured
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Models can define which connection to use, by name. To use a named
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connection, set the `db_connection` property in the model's Meta class
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to the name of the connection. The name used must be a key in
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settings.DATABASES, of course.
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>>> from django.db import models
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>>> class Artist(models.Model):
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... name = models.CharField(maxlength=100)
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... alive = models.BooleanField(default=True)
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...
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... def __str__(self):
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... return self.name
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...
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... class Meta:
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... app_label = 'mdb'
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... db_connection = 'a'
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...
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>>> class Widget(models.Model):
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... code = models.CharField(maxlength=10, unique=True)
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... weight = models.IntegerField()
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...
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... def __str__(self):
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... return self.code
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...
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... class Meta:
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... app_label = 'mdb'
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... db_connection = 'b'
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But they don't have to. Multiple database support is entirely optional
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and has no impact on your application if you don't use it.
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>>> class Vehicle(models.Model):
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... make = models.CharField(maxlength=20)
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... model = models.CharField(maxlength=20)
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... year = models.IntegerField()
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...
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... def __str__(self):
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... return "%d %s %s" % (self.year, self.make, self.model)
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...
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... class Meta:
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... app_label = 'mdb'
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>>> Artist._meta.connection.settings.DATABASE_NAME == \
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... connections['a'].connection.settings.DATABASE_NAME
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True
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>>> Widget._meta.connection.settings.DATABASE_NAME == \
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... connections['b'].connection.settings.DATABASE_NAME
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True
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>>> Vehicle._meta.connection.settings.DATABASE_NAME == \
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... connection.settings.DATABASE_NAME
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True
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>>> Artist._meta.connection.settings.DATABASE_NAME == \
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... Widget._meta.connection.settings.DATABASE_NAME
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False
|
||||
>>> Artist._meta.connection.settings.DATABASE_NAME == \
|
||||
... Vehicle._meta.connection.settings.DATABASE_NAME
|
||||
False
|
||||
|
||||
"""
|
||||
|
||||
def cleanup():
|
||||
|
||||
Loading…
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Reference in New Issue
Block a user