sqlalchemy.orm.attributes.QueryableAttribute

class documentation

class QueryableAttribute(interfaces._MappedAttribute, interfaces.InspectionAttr, interfaces.PropComparator, traversals.HasCopyInternals, roles.JoinTargetRole, roles.OnClauseRole, sql_base.Immutable, sql_base.MemoizedHasCacheKey):

Known subclasses: sqlalchemy.orm.attributes.Mapped

View In Hierarchy

Base class for :term:`descriptor` objects that intercept attribute events on behalf of a .MapperProperty object. The actual .MapperProperty is accessible via the .QueryableAttribute.property attribute.

See Also

.InstrumentedAttribute

.MapperProperty

_orm.Mapper.all_orm_descriptors

_orm.Mapper.attrs

Method	`__clause_element__`	Undocumented
Method	`__getattr__`	Undocumented
Method	`__init__`	Undocumented
Method	`__reduce__`	Undocumented
Method	`__str__`	Undocumented
Method	`_bulk_update_tuples`	Return setter tuples for a bulk UPDATE.
Method	`_clone`	Undocumented
Method	`adapt_to_entity`	Return a copy of this PropComparator which will use the given `.AliasedInsp` to produce corresponding expressions.
Method	`and_`	Add additional criteria to the ON clause that's represented by this relationship attribute.
Method	`get_history`	Undocumented
Method	`hasparent`	Undocumented
Method	`label`	Undocumented
Method	`of_type`	Redefine this object in terms of a polymorphic subclass, `_orm.with_polymorphic` construct, or `_orm.aliased` construct.
Method	`operate`	Operate on an argument.
Method	`reverse_operate`	Reverse operate on an argument.
Class Variable	`__visit_name__`	Undocumented
Class Variable	`_cache_key_traversal`	Undocumented
Class Variable	`is_attribute`	True if this object is a Python :term:`descriptor`.
Instance Variable	`_extra_criteria`	Undocumented
Instance Variable	`_of_type`	Undocumented
Instance Variable	`_parententity`	Undocumented
Instance Variable	`class_`	Undocumented
Instance Variable	`comparator`	Undocumented
Instance Variable	`impl`	Undocumented
Instance Variable	`key`	Undocumented
Property	`_annotations`	Undocumented
Property	`_entity_namespace`	Undocumented
Property	`_from_objects`	Undocumented
Property	`_impl_uses_objects`	Undocumented
Property	`_supports_population`	Undocumented
Property	`expression`	The SQL expression object represented by this `.QueryableAttribute`.
Property	`info`	Return the 'info' dictionary for the underlying SQL element.
Property	`parent`	Return an inspection instance representing the parent.
Property	`property`	Return the `.MapperProperty` associated with this `.QueryableAttribute`.

Inherited from _MappedAttribute:

Class Variable __slots__ 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_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_instance`	True if this object is an instance of `.InstanceState`.
Class Variable	`is_mapper`	True if this object is an instance of `_orm.Mapper`.
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`.

Inherited from PropComparator:

Static Method	`any_op`	Undocumented
Static Method	`has_op`	Undocumented
Static Method	`of_type_op`	Undocumented
Method	`any`	Return true if this collection contains any member that meets the given criterion.
Method	`has`	Return true if this element references a member which meets the given criterion.
Class Variable	`__slots__`	Undocumented
Instance Variable	`_adapt_to_entity`	Undocumented
Instance Variable	`prop`	Undocumented
Property	`_parentmapper`	legacy; this is renamed to _parententity to be compatible with QueryableAttribute.
Property	`_propagate_attrs`	Undocumented
Property	`adapter`	Produce a callable that adapts column expressions to suit an aliased version of this comparator.

Inherited from ColumnOperators (via PropComparator):

Method	`__add__`	Implement the `+` operator.
Method	`__contains__`	Undocumented
Method	`__div__`	Implement the `/` operator.
Method	`__eq__`	Implement the `==` operator.
Method	`__ge__`	Implement the `>=` operator.
Method	`__getitem__`	Implement the [] operator.
Method	`__gt__`	Implement the `>` operator.
Method	`__le__`	Implement the `<=` operator.
Method	`__lshift__`	implement the << operator.
Method	`__lt__`	Implement the `<` operator.
Method	`__mod__`	Implement the `%` operator.
Method	`__mul__`	Implement the `*` operator.
Method	`__ne__`	Implement the `!=` operator.
Method	`__neg__`	Implement the `-` operator.
Method	`__radd__`	Implement the `+` operator in reverse.
Method	`__rdiv__`	Implement the `/` operator in reverse.
Method	`__rmod__`	Implement the `%` operator in reverse.
Method	`__rmul__`	Implement the `*` operator in reverse.
Method	`__rshift__`	implement the >> operator.
Method	`__rsub__`	Implement the `-` operator in reverse.
Method	`__rtruediv__`	Implement the `//` operator in reverse.
Method	`__sub__`	Implement the `-` operator.
Method	`__truediv__`	Implement the `//` operator.
Method	`all_`	Produce an `_expression.all_` clause against the parent object.
Method	`any_`	Produce an `_expression.any_` clause against the parent object.
Method	`asc`	Produce a `_expression.asc` clause against the parent object.
Method	`between`	Produce a `_expression.between` clause against the parent object, given the lower and upper range.
Method	`collate`	Produce a `_expression.collate` clause against the parent object, given the collation string.
Method	`concat`	Implement the 'concat' operator.
Method	`contains`	Implement the 'contains' operator.
Method	`desc`	Produce a `_expression.desc` clause against the parent object.
Method	`distinct`	Produce a `_expression.distinct` clause against the parent object.
Method	`endswith`	Implement the 'endswith' operator.
Method	`ilike`	Implement the `ilike` operator, e.g. case insensitive LIKE.
Method	`in_`	Implement the `in` operator.
Method	`is_`	Implement the `IS` operator.
Method	`is_distinct_from`	Implement the `IS DISTINCT FROM` operator.
Method	`is_not`	Implement the `IS NOT` operator.
Method	`is_not_distinct_from`	Implement the `IS NOT DISTINCT FROM` operator.
Method	`like`	Implement the `like` operator.
Method	`match`	Implements a database-specific 'match' operator.
Method	`not_ilike`	implement the `NOT ILIKE` operator.
Method	`not_in`	implement the `NOT IN` operator.
Method	`not_like`	implement the `NOT LIKE` operator.
Method	`nulls_first`	Produce a `_expression.nulls_first` clause against the parent object.
Method	`nulls_last`	Produce a `_expression.nulls_last` clause against the parent object.
Method	`regexp_match`	Implements a database-specific 'regexp match' operator.
Method	`regexp_replace`	Implements a database-specific 'regexp replace' operator.
Method	`startswith`	Implement the `startswith` operator.
Class Variable	`timetuple`	Hack, allows datetime objects to be compared on the LHS.

Inherited from Operators (via PropComparator, ColumnOperators):

Method	`__and__`	Implement the `&` operator.
Method	`__invert__`	Implement the `~` operator.
Method	`__or__`	Implement the `\|` operator.
Method	`bool_op`	Return a custom boolean operator.
Method	`op`	Produce a generic operator function.

Inherited from HasCopyInternals:

Method _copy_internals Reassign internal elements to be clones of themselves.

Inherited from JoinTargetRole:

Class Variable _role_name Undocumented

Inherited from AllowsLambdaRole (via JoinTargetRole):

Class Variable allows_lambda Undocumented

Inherited from UsesInspection (via JoinTargetRole):

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

Inherited from SQLRole (via JoinTargetRole, StructuralRole):

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

Inherited from OnClauseRole:

Class Variable _role_name Undocumented

Inherited from AllowsLambdaRole (via OnClauseRole):

Class Variable allows_lambda Undocumented

Inherited from SQLRole (via OnClauseRole, StructuralRole):

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

Inherited from Immutable:

Method	`_copy_internals`	Undocumented
Method	`params`	Undocumented
Method	`unique_params`	Undocumented
Class Variable	`_is_immutable`	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
Method	`_gen_cache_key`	return an optional cache key.
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

def __clause_element__(self):

overrides sqlalchemy.orm.interfaces.PropComparator.__clause_element__

Undocumented

def __getattr__(self, key):

Undocumented

def __init__(self, class_, key, parententity, impl=None, comparator=None, of_type=None, extra_criteria=()):

overrides sqlalchemy.orm.interfaces.PropComparator.__init__

Undocumented

def __reduce__(self):

Undocumented

def __str__(self):

Undocumented

def _bulk_update_tuples(self, value):

overrides sqlalchemy.orm.interfaces.PropComparator._bulk_update_tuples

Return setter tuples for a bulk UPDATE.

def _clone(self, **kw):

overrides sqlalchemy.sql.traversals.HasCopyInternals._clone

Undocumented

def adapt_to_entity(self, adapt_to_entity):

overrides sqlalchemy.orm.interfaces.PropComparator.adapt_to_entity

Return a copy of this PropComparator which will use the given .AliasedInsp to produce corresponding expressions.

def and_(self, *other):

overrides sqlalchemy.orm.interfaces.PropComparator.and_

Add additional criteria to the ON clause that's represented by this relationship attribute.

E.g.:

stmt = select(User).join(
    User.addresses.and_(Address.email_address != 'foo')
)

stmt = select(User).options(
    joinedload(User.addresses.and_(Address.email_address != 'foo'))
)

New in version 1.4.

See Also

:ref:`orm_queryguide_join_on_augmented`

:ref:`loader_option_criteria`

.with_loader_criteria

def get_history(self, instance, passive=PASSIVE_OFF):

Undocumented

def hasparent(self, state, optimistic=False):

Undocumented

def label(self, name):

Undocumented

def of_type(self, entity):

overrides sqlalchemy.orm.interfaces.PropComparator.of_type

Redefine this object in terms of a polymorphic subclass, _orm.with_polymorphic construct, or _orm.aliased construct.

Returns a new PropComparator from which further criterion can be evaluated.

e.g.:

query.join(Company.employees.of_type(Engineer)).\
   filter(Engineer.name=='foo')

:ref:`inheritance_of_type`

Parameters
entity	Undocumented
class_	a class or mapper indicating that criterion will be against this specific subclass.

def operate(self, op, *other, **kwargs):

overrides sqlalchemy.sql.operators.Operators.operate

Operate on an argument.

This is the lowest level of operation, raises NotImplementedError by default.

Overriding this on a subclass can allow common behavior to be applied to all operations. For example, overriding .ColumnOperators to apply func.lower() to the left and right side:

class MyComparator(ColumnOperators):
    def operate(self, op, other):
        return op(func.lower(self), func.lower(other))

Parameters
op	Operator callable.
*other	the 'other' side of the operation. Will be a single scalar for most operations.
**kwargs	modifiers. These may be passed by special operators such as `ColumnOperators.contains`.

def reverse_operate(self, op, other, **kwargs):

overrides sqlalchemy.sql.operators.Operators.reverse_operate

Reverse operate on an argument.

Usage is the same as operate.

__visit_name__: str =

overrides sqlalchemy.orm.interfaces.PropComparator.__visit_name__

Undocumented

_cache_key_traversal =

Undocumented

is_attribute: bool =

overrides sqlalchemy.orm.base.InspectionAttr.is_attribute

True if this object is a Python :term:`descriptor`.

This can refer to one of many types. Usually a .QueryableAttribute which handles attributes events on behalf of a .MapperProperty. But can also be an extension type such as .AssociationProxy or .hybrid_property. The .InspectionAttr.extension_type will refer to a constant identifying the specific subtype.

See Also

_orm.Mapper.all_orm_descriptors

_extra_criteria =

Undocumented

_of_type =

Undocumented

_parententity =

overrides sqlalchemy.orm.interfaces.PropComparator._parententity

Undocumented

class_ =

Undocumented

comparator =

Undocumented

impl =

Undocumented

key =

Undocumented

@property
_annotations =

Undocumented

@property
_entity_namespace =

Undocumented

@property
_from_objects =

Undocumented

@property
_impl_uses_objects =

Undocumented

@util.memoized_property
_supports_population =

Undocumented

@util.memoized_property
expression =

The SQL expression object represented by this .QueryableAttribute.

This will typically be an instance of a _sql.ColumnElement subclass representing a column expression.

@util.memoized_property
info =

overrides sqlalchemy.orm.interfaces.PropComparator.info

Return the 'info' dictionary for the underlying SQL element.

The behavior here is as follows:

If the attribute is a column-mapped property, i.e. .ColumnProperty, which is mapped directly to a schema-level _schema.Column object, this attribute will return the .SchemaItem.info dictionary associated with the core-level _schema.Column object.
If the attribute is a .ColumnProperty but is mapped to any other kind of SQL expression other than a _schema.Column, the attribute will refer to the .MapperProperty.info dictionary associated directly with the .ColumnProperty, assuming the SQL expression itself does not have its own .info attribute (which should be the case, unless a user-defined SQL construct has defined one).
If the attribute refers to any other kind of .MapperProperty, including .RelationshipProperty, the attribute will refer to the .MapperProperty.info dictionary associated with that .MapperProperty.
To access the .MapperProperty.info dictionary of the .MapperProperty unconditionally, including for a .ColumnProperty that's associated directly with a _schema.Column, the attribute can be referred to using .QueryableAttribute.property attribute, as MyClass.someattribute.property.info.

See Also

.SchemaItem.info

.MapperProperty.info

@util.memoized_property
parent =

Return an inspection instance representing the parent.

This will be either an instance of _orm.Mapper or .AliasedInsp, depending upon the nature of the parent entity which this attribute is associated with.

@util.memoized_property
property =

overrides sqlalchemy.orm.interfaces.PropComparator.property

Return the .MapperProperty associated with this .QueryableAttribute.

Return values here will commonly be instances of .ColumnProperty or .RelationshipProperty.