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magic-removal: Renamed 'this' and 'rel' variables to 'source' and 'target', to clarify some confusing cases in m2m fields where 'this' object is the related field. 

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2363 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee 2006-02-19 08:49:59 +00:00
parent b730754415
commit f9d95dc4ad
1 changed files with 38 additions and 38 deletions
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76
django/db/models/fields/related.py
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@ -94,17 +94,17 @@ class SingleRelatedObjectDescriptor(object):
setattr(instance, cache_name, rel_obj)
return rel_obj
def _add_m2m_items(rel_manager_inst, managerclass, rel_model, join_table, this_col_name,
rel_col_name, this_pk_val, *objs, **kwargs):
def _add_m2m_items(rel_manager_inst, managerclass, rel_model, join_table, source_col_name,
target_col_name, source_pk_val, *objs, **kwargs):
# Utility function used by the ManyRelatedObjectsDescriptors
# to do addition to a many-to-many field.
# rel_manager_inst: the RelatedManager instance
# managerclass: class that can create and save new objects
# rel_model: the model class of the 'related' object
# join_table: name of the m2m link table
# this_col_name: the PK colname in join_table for 'this' object
# rel_col_name: the PK colname in join_table for the related object
# this_pk_val: the primary key for 'this' object
# source_col_name: the PK colname in join_table for the source object
# target_col_name: the PK colname in join_table for the target object
# source_pk_val: the primary key for the source object
# *objs - objects to add, or **kwargs to create new objects
from django.db import connection
@ -124,9 +124,9 @@ def _add_m2m_items(rel_manager_inst, managerclass, rel_model, join_table, this_c
new_ids = set([obj._get_pk_val() for obj in objs])
cursor = connection.cursor()
cursor.execute("SELECT %s FROM %s WHERE %s = %%s AND %s IN (%s)" % \
(rel_col_name, join_table, this_col_name,
rel_col_name, ",".join(['%s'] * len(new_ids))),
[this_pk_val] + list(new_ids))
(target_col_name, join_table, source_col_name,
target_col_name, ",".join(['%s'] * len(new_ids))),
[source_pk_val] + list(new_ids))
if cursor.rowcount is not None and cursor.rowcount > 0:
existing_ids = set([row[0] for row in cursor.fetchmany(cursor.rowcount)])
else:
@ -135,19 +135,19 @@ def _add_m2m_items(rel_manager_inst, managerclass, rel_model, join_table, this_c
# Add the ones that aren't there already
for obj_id in (new_ids - existing_ids):
cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
(join_table, this_col_name, rel_col_name),
[this_pk_val, obj_id])
(join_table, source_col_name, target_col_name),
[source_pk_val, obj_id])
connection.commit()
def _remove_m2m_items(rel_model, join_table, this_col_name,
rel_col_name, this_pk_val, *objs):
def _remove_m2m_items(rel_model, join_table, source_col_name,
target_col_name, source_pk_val, *objs):
# Utility function used by the ManyRelatedObjectsDescriptors
# to do removal from a many-to-many field.
# rel_model: the model class of the 'related' object
# join_table: name of the m2m link table
# this_col_name: the PK colname in join_table for 'this' object
# rel_col_name: the PK colname in join_table for the related object
# this_pk_val: the primary key for 'this' object
# source_col_name: the PK colname in join_table for the source object
# target_col_name: the PK colname in join_table for the target object
# source_pk_val: the primary key for the source object
# *objs - objects to remove
from django.db import connection
@ -159,21 +159,21 @@ def _remove_m2m_items(rel_model, join_table, this_col_name,
cursor = connection.cursor()
for obj in objs:
cursor.execute("DELETE FROM %s WHERE %s = %%s AND %s = %%s" % \
(join_table, this_col_name, rel_col_name),
[this_pk_val, obj._get_pk_val()])
(join_table, source_col_name, target_col_name),
[source_pk_val, obj._get_pk_val()])
connection.commit()
def _clear_m2m_items(join_table, this_col_name, this_pk_val):
def _clear_m2m_items(join_table, source_col_name, source_pk_val):
# Utility function used by the ManyRelatedObjectsDescriptors
# to clear all from a many-to-many field.
# join_table: name of the m2m link table
# this_col_name: the PK colname in join_table for 'this' object
# this_pk_val: the primary key for 'this' object
# source_col_name: the PK colname in join_table for the source object
# source_pk_val: the primary key for the source object
from django.db import connection
cursor = connection.cursor()
cursor.execute("DELETE FROM %s WHERE %s = %%s" % \
(join_table, this_col_name),
[this_pk_val])
(join_table, source_col_name),
[source_pk_val])
connection.commit()
class ManyRelatedObjectsDescriptor(object):
@ -200,8 +200,8 @@ class ManyRelatedObjectsDescriptor(object):
this_opts = instance.__class__._meta
rel_opts = rel_model._meta
join_table = qn(self.related.field.m2m_db_table())
this_col_name = qn(self.related.field.m2m_reverse_name())
rel_col_name = qn(self.related.field.m2m_column_name())
source_col_name = qn(self.related.field.m2m_reverse_name())
target_col_name = qn(self.related.field.m2m_column_name())
# Dynamically create a class that subclasses the related
# model's default manager.
@ -217,8 +217,8 @@ class ManyRelatedObjectsDescriptor(object):
return superclass.add(self, **kwargs)
else:
def add(self, *objs, **kwargs):
_add_m2m_items(self, superclass, rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs, **kwargs)
_add_m2m_items(self, superclass, rel_model, join_table, source_col_name,
target_col_name, instance._get_pk_val(), *objs, **kwargs)
add.alters_data = True
if rel_type == "o2m":
@ -226,8 +226,8 @@ class ManyRelatedObjectsDescriptor(object):
pass # TODO
else:
def remove(self, *objs):
_remove_m2m_items(rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs)
_remove_m2m_items(rel_model, join_table, source_col_name,
target_col_name, instance._get_pk_val(), *objs)
remove.alters_data = True
if rel_type == "o2m":
@ -235,7 +235,7 @@ class ManyRelatedObjectsDescriptor(object):
pass # TODO
else:
def clear(self):
_clear_m2m_items(join_table, this_col_name, instance._get_pk_val())
_clear_m2m_items(join_table, source_col_name, instance._get_pk_val())
clear.alters_data = True
manager = RelatedManager()
@ -268,8 +268,8 @@ class ReverseManyRelatedObjectsDescriptor(object):
rel_model = self.field.rel.to
rel_opts = rel_model._meta
join_table = qn(self.field.m2m_db_table())
this_col_name = qn(self.field.m2m_column_name())
rel_col_name = qn(self.field.m2m_reverse_name())
source_col_name = qn(self.field.m2m_column_name())
target_col_name = qn(self.field.m2m_reverse_name())
# Dynamically create a class that subclasses the related
# model's default manager.
@ -280,23 +280,23 @@ class ReverseManyRelatedObjectsDescriptor(object):
return superclass.get_query_set(self).extra(
tables=(join_table,),
where=[
'%s.%s = %s.%s' % (qn(rel_opts.db_table), qn(rel_opts.pk.column), join_table, rel_col_name),
'%s.%s = %%s' % (join_table, this_col_name)
'%s.%s = %s.%s' % (qn(rel_opts.db_table), qn(rel_opts.pk.column), join_table, target_col_name),
'%s.%s = %%s' % (join_table, source_col_name)
],
params = [instance._get_pk_val()]
)
def add(self, *objs, **kwargs):
_add_m2m_items(self, superclass, rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs, **kwargs)
_add_m2m_items(self, superclass, rel_model, join_table, source_col_name,
target_col_name, instance._get_pk_val(), *objs, **kwargs)
add.alters_data = True
def remove(self, *objs):
_remove_m2m_items(rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs)
_remove_m2m_items(rel_model, join_table, source_col_name,
target_col_name, instance._get_pk_val(), *objs)
remove.alters_data = True
def clear(self):
_clear_m2m_items(join_table, this_col_name, instance._get_pk_val())
_clear_m2m_items(join_table, source_col_name, instance._get_pk_val())
clear.alters_data = True
manager = RelatedManager()