def get_for_model(self, model, model_db=None):
model_db = model_db or router.db_for_write(model)
content_type = _get_content_type(model, self.db)
return self.filter(
content_type=content_type,
db=model_db,
)
def get_for_model(self, model, model_db=None):
model_db = model_db or router.db_for_write(model)
content_type = _get_content_type(model, self.db)
return self.filter(
content_type=content_type,
db=model_db,
)
def get_deleted(self, model, model_db=None):
# Try to do a faster JOIN.
model_db = model_db or router.db_for_write(model)
connection = connections[self.db]
if self.db == model_db and connection.vendor in ("sqlite",
"postgresql",
"oracle"):
content_type = _get_content_type(model, self.db)
subquery = SubquerySQL(
"""
SELECT MAX(V.{id})
FROM {version} V
LEFT JOIN {model} ON V.{object_id} = CAST({model}.{model_id} as {str})
WHERE
V.{db} = %s AND
V.{content_type_id} = %s AND
{model}.{model_id} IS NULL
GROUP BY V.{object_id}
""".format(
id=connection.ops.quote_name("id"),
version=connection.ops.quote_name(Version._meta.db_table),
model=connection.ops.quote_name(model._meta.db_table),
model_id=connection.ops.quote_name(
model._meta.pk.db_column or model._meta.pk.attname),
object_id=connection.ops.quote_name("object_id"),
str=Version._meta.get_field("object_id").db_type(
connection),
db=connection.ops.quote_name("db"),
content_type_id=connection.ops.quote_name(
"content_type_id"),
),
(model_db, content_type.id),
output_field=Version._meta.pk,
)
else:
# We have to use a slow subquery.
subquery = self.get_for_model(model, model_db=model_db).exclude(
object_id__in=list(
model._default_manager.using(model_db).values_list(
"pk", flat=True).order_by().iterator()),
).values_list("object_id").annotate(
latest_pk=models.Max("pk")).order_by().values_list("latest_pk",
flat=True)
# Perform the subquery.
return self.filter(pk__in=subquery, )
def field_dict(self):
"""
A dictionary mapping field names to field values in this version
of the model.
This method will follow parent links, if present.
"""
field_dict = self._local_field_dict
# Add parent data.
for parent_model, field in self._model._meta.concrete_model._meta.parents.items():
content_type = _get_content_type(parent_model, self._state.db)
parent_id = field_dict[field.attname]
parent_version = self.revision.version_set.get(
content_type=content_type,
object_id=parent_id,
db=self.db,
)
field_dict.update(parent_version.field_dict)
return field_dict
def field_dict(self):
"""
A dictionary mapping field names to field values in this version
of the model.
This method will follow parent links, if present.
"""
field_dict = self._local_field_dict
# Add parent data.
for parent_model, field in self._model._meta.concrete_model._meta.parents.items():
content_type = _get_content_type(parent_model, self._state.db)
parent_id = field_dict[field.attname]
parent_version = self.revision.version_set.get(
content_type=content_type,
object_id=parent_id,
db=self.db,
)
field_dict.update(parent_version.field_dict)
return field_dict
def get_deleted(self, model, model_db=None):
# Try to do a faster JOIN.
model_db = model_db or router.db_for_write(model)
connection = connections[self.db]
if self.db == model_db and connection.vendor in ("sqlite", "postgresql", "oracle"):
content_type = _get_content_type(model, self.db)
subquery = SubquerySQL(
"""
SELECT MAX(V.{id})
FROM {version} V
LEFT JOIN {model} ON V.{object_id} = CAST({model}.{model_id} as {str})
WHERE
V.{db} = %s AND
V.{content_type_id} = %s AND
{model}.{model_id} IS NULL
GROUP BY V.{object_id}
""".format(
id=connection.ops.quote_name("id"),
version=connection.ops.quote_name(Version._meta.db_table),
model=connection.ops.quote_name(model._meta.db_table),
model_id=connection.ops.quote_name(model._meta.pk.db_column or model._meta.pk.attname),
object_id=connection.ops.quote_name("object_id"),
str=Version._meta.get_field("object_id").db_type(connection),
db=connection.ops.quote_name("db"),
content_type_id=connection.ops.quote_name("content_type_id"),
),
(model_db, content_type.id),
output_field=Version._meta.pk,
)
else:
# We have to use a slow subquery.
subquery = self.get_for_model(model, model_db=model_db).exclude(
object_id__in=list(
model._default_manager.using(model_db).values_list("pk", flat=True).order_by().iterator()
),
).values_list("object_id").annotate(
latest_pk=models.Max("pk")
).order_by().values_list("latest_pk", flat=True)
# Perform the subquery.
return self.filter(
pk__in=subquery,
)
