sqlalchemy.orm.util.Bundle

class documentation

class Bundle(ORMColumnsClauseRole, SupportsCloneAnnotations, sql_base.MemoizedHasCacheKey, InspectionAttr):

Known subclasses: sqlalchemy.orm.properties.CompositeProperty.CompositeBundle

A grouping of SQL expressions that are returned by a .Query under one namespace.

The .Bundle essentially allows nesting of the tuple-based results returned by a column-oriented _query.Query object. It also is extensible via simple subclassing, where the primary capability to override is that of how the set of expressions should be returned, allowing post-processing as well as custom return types, without involving ORM identity-mapped classes.

New in version 0.9.0.

See Also

:ref:`bundles`

Method	`__clause_element__`	Undocumented
Method	`__init__`	Construct a new `.Bundle`.
Method	`_clone`	Undocumented
Method	`_gen_cache_key`	return an optional cache key.
Method	`create_row_processor`	Produce the "row processing" function for this `.Bundle`.
Method	`label`	Provide a copy of this `.Bundle` passing a new label.
Class Variable	`_propagate_attrs`	Undocumented
Class Variable	`is_aliased_class`	True if this object is an instance of `.AliasedClass`.
Class Variable	`is_bundle`	True if this object is an instance of `.Bundle`.
Class Variable	`is_clause_element`	True if this object is an instance of `_expression.ClauseElement`.
Class Variable	`is_mapper`	True if this object is an instance of `_orm.Mapper`.
Instance Variable	`_label`	Undocumented
Instance Variable	`c`	An alias for `.Bundle.columns`.
Instance Variable	`columns`	A namespace of SQL expressions referred to by this `.Bundle`.
Instance Variable	`exprs`	Undocumented
Instance Variable	`name`	Undocumented
Instance Variable	`single_entity`	If True, queries for a single Bundle will be returned as a single entity, rather than an element within a keyed tuple.
Property	`clauses`	Undocumented
Property	`entity`	Undocumented
Property	`entity_namespace`	Undocumented
Property	`mapper`	Undocumented

Inherited from ORMColumnsClauseRole:

Class Variable _role_name Undocumented

Inherited from ColumnsClauseRole (via ORMColumnsClauseRole):

Property _select_iterable Undocumented

Inherited from AllowsLambdaRole (via ORMColumnsClauseRole, ColumnsClauseRole):

Class Variable allows_lambda Undocumented

Inherited from UsesInspection (via ORMColumnsClauseRole, ColumnsClauseRole):

Class Variable	`_post_inspect`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SQLRole (via ORMColumnsClauseRole, ColumnsClauseRole, ColumnListRole):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SupportsCloneAnnotations:

Method	`_annotate`	return a copy of this ClauseElement with annotations updated by the given dictionary.
Method	`_deannotate`	return a copy of this `_expression.ClauseElement` with annotations removed.
Method	`_with_annotations`	return a copy of this ClauseElement with annotations replaced by the given dictionary.
Class Variable	`_clone_annotations_traverse_internals`	Undocumented

Inherited from SupportsAnnotations (via SupportsCloneAnnotations):

Property _annotations_cache_key Undocumented

Inherited from MemoizedHasCacheKey:

Method _generate_cache_key return a cache key.

Inherited from HasCacheKey (via MemoizedHasCacheKey):

Class Variable	`inherit_cache`	Indicate if this `.HasCacheKey` instance should make use of the cache key generation scheme used by its immediate superclass.
Class Method	`_generate_cache_attrs`	generate cache key dispatcher for a new class.
Class Method	`_generate_cache_key_for_object`	Undocumented
Class Variable	`__slots__`	Undocumented
Class Variable	`_hierarchy_supports_caching`	private attribute which may be set to False to prevent the inherit_cache warning from being emitted for a hierarchy of subclasses.
Class Variable	`_is_has_cache_key`	Undocumented

Inherited from InspectionAttr:

Class Variable	`__slots__`	Undocumented
Class Variable	`_is_internal_proxy`	True if this object is an internal proxy object.
Class Variable	`is_attribute`	True if this object is a Python :term:`descriptor`.
Class Variable	`is_instance`	True if this object is an instance of `.InstanceState`.
Class Variable	`is_property`	True if this object is an instance of `.MapperProperty`.
Class Variable	`is_selectable`	Return True if this object is an instance of `_expression.Selectable`.

def __clause_element__(self):

Undocumented

def __init__(self, name, *exprs, **kw):

overridden in sqlalchemy.orm.properties.CompositeProperty.CompositeBundle

Construct a new .Bundle.

e.g.:

bn = Bundle("mybundle", MyClass.x, MyClass.y)

for row in session.query(bn).filter(
        bn.c.x == 5).filter(bn.c.y == 4):
    print(row.mybundle.x, row.mybundle.y)

Parameters
name	name of the bundle.
*exprs	columns or SQL expressions comprising the bundle.
**kw	Undocumented
single_entity=False	if True, rows for this `.Bundle` can be returned as a "single entity" outside of any enclosing tuple in the same manner as a mapped entity.

def _clone(self):

Undocumented

def _gen_cache_key(self, anon_map, bindparams):

overrides sqlalchemy.sql.traversals.HasCacheKey._gen_cache_key

return an optional cache key.

The cache key is a tuple which can contain any series of objects that are hashable and also identifies this object uniquely within the presence of a larger SQL expression or statement, for the purposes of caching the resulting query.

The cache key should be based on the SQL compiled structure that would ultimately be produced. That is, two structures that are composed in exactly the same way should produce the same cache key; any difference in the structures that would affect the SQL string or the type handlers should result in a different cache key.

If a structure cannot produce a useful cache key, the NO_CACHE symbol should be added to the anon_map and the method should return None.

def create_row_processor(self, query, procs, labels):

overridden in sqlalchemy.orm.properties.CompositeProperty.CompositeBundle

Produce the "row processing" function for this .Bundle.

May be overridden by subclasses.