sqlalchemy.orm.descriptor_props.DescriptorProperty

class documentation

class DescriptorProperty(MapperProperty):

Known subclasses: sqlalchemy.orm.properties.CompositeProperty, sqlalchemy.orm.properties.ConcreteInheritedProperty, sqlalchemy.orm.properties.SynonymProperty

View In Hierarchy

.MapperProperty which proxies access to a user-defined descriptor.

Method	`instrument_class`	Hook called by the Mapper to the property to initiate instrumentation of the class attribute managed by this MapperProperty.
Class Variable	`_links_to_entity`	True if this MapperProperty refers to a mapped entity.
Class Variable	`doc`	Undocumented
Class Variable	`uses_objects`	Undocumented
Instance Variable	`descriptor`	Undocumented

Inherited from MapperProperty:

Method	`__init__`	Undocumented
Method	`__repr__`	Undocumented
Method	`_memoized_attr_info`	Info dictionary associated with the object, allowing user-defined data to be associated with this `.InspectionAttr`.
Method	`cascade_iterator`	Iterate through instances related to the given instance for a particular 'cascade', starting with this MapperProperty.
Method	`create_row_processor`	Produce row processing functions and append to the given set of populators lists.
Method	`do_init`	Perform subclass-specific initialization post-mapper-creation steps.
Method	`init`	Called after all mappers are created to assemble relationships between mappers and perform other post-mapper-creation initialization steps.
Method	`merge`	Merge the attribute represented by this `MapperProperty` from source to destination object.
Method	`post_instrument_class`	Perform instrumentation adjustments that need to occur after init() has completed.
Method	`set_parent`	Set the parent mapper that references this MapperProperty.
Method	`setup`	Called by Query for the purposes of constructing a SQL statement.
Class Variable	`__slots__`	Undocumented
Class Variable	`_cache_key_traversal`	Undocumented
Class Variable	`cascade`	The set of 'cascade' attribute names.
Class Variable	`is_property`	Part of the InspectionAttr interface; states this object is a mapper property.
Instance Variable	`_configure_finished`	Undocumented
Instance Variable	`_configure_started`	Undocumented
Instance Variable	`parent`	Undocumented
Property	`class_attribute`	Return the class-bound descriptor corresponding to this `.MapperProperty`.

Inherited from HasCacheKey (via MapperProperty):

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.
Method	`_generate_cache_key`	return a cache key.
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 (via MapperProperty):

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_attribute`	True if this object is a Python :term:`descriptor`.
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_selectable`	Return True if this object is an instance of `_expression.Selectable`.

Inherited from MemoizedSlots (via MapperProperty):

Method	`__getattr__`	Undocumented
Method	`_fallback_getattr`	Undocumented

def instrument_class(self, mapper):

overrides sqlalchemy.orm.interfaces.MapperProperty.instrument_class

overridden in sqlalchemy.orm.properties.CompositeProperty

Hook called by the Mapper to the property to initiate instrumentation of the class attribute managed by this MapperProperty.

The MapperProperty here will typically call out to the attributes module to set up an InstrumentedAttribute.

This step is the first of two steps to set up an InstrumentedAttribute, and is called early in the mapper setup process.

The second step is typically the init_class_attribute step, called from StrategizedProperty via the post_instrument_class() hook. This step assigns additional state to the InstrumentedAttribute (specifically the "impl") which has been determined after the MapperProperty has determined what kind of persistence management it needs to do (e.g. scalar, object, collection, etc).

_links_to_entity: bool =

overrides sqlalchemy.orm.interfaces.MapperProperty._links_to_entity

True if this MapperProperty refers to a mapped entity.

Should only be True for RelationshipProperty, False for all others.

doc =

overridden in sqlalchemy.orm.properties.SynonymProperty

Undocumented

uses_objects: bool =

overridden in sqlalchemy.orm.properties.SynonymProperty

Undocumented

descriptor =

overridden in sqlalchemy.orm.properties.CompositeProperty, sqlalchemy.orm.properties.ConcreteInheritedProperty, sqlalchemy.orm.properties.SynonymProperty

Undocumented