sqlalchemy.orm.properties.CompositeProperty

class documentation

class CompositeProperty(DescriptorProperty):

Defines a "composite" mapped attribute, representing a collection of columns as one attribute.

.CompositeProperty is constructed using the .composite function.

See Also

:ref:`mapper_composite`

Class	`Comparator`	Produce boolean, comparison, and other operators for `.CompositeProperty` attributes.
Class	`CompositeBundle`	Undocumented
Method	`__init__`	Return a composite column-based property for use with a Mapper.
Method	`__str__`	Undocumented
Method	`_comparator_factory`	Undocumented
Method	`_create_descriptor`	Create the Python descriptor that will serve as the access point on instances of the mapped class.
Method	`_setup_arguments_on_columns`	Propagate configuration arguments made on this composite to the target columns, for those that apply.
Method	`_setup_event_handlers`	Establish events that populate/expire the composite attribute.
Method	`do_init`	Initialization which occurs after the `.CompositeProperty` has been associated with its parent mapper.
Method	`get_history`	Provided for userland code that uses attributes.get_history().
Method	`instrument_class`	Hook called by the Mapper to the property to initiate instrumentation of the class attribute managed by this MapperProperty.
Constant	`_COMPOSITE_FGET`	Undocumented
Instance Variable	`active_history`	Undocumented
Instance Variable	`attrs`	Undocumented
Instance Variable	`comparator_factory`	Undocumented
Instance Variable	`composite_class`	Undocumented
Instance Variable	`deferred`	Undocumented
Instance Variable	`descriptor`	Undocumented
Instance Variable	`group`	Undocumented
Instance Variable	`info`	Undocumented
Property	`_attribute_keys`	Undocumented
Property	`_comparable_elements`	Undocumented
Property	`columns`	Undocumented
Property	`props`	Undocumented

Inherited from DescriptorProperty:

Class Variable	`_links_to_entity`	True if this MapperProperty refers to a mapped entity.
Class Variable	`doc`	Undocumented
Class Variable	`uses_objects`	Undocumented

Inherited from MapperProperty (via DescriptorProperty):

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	`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 DescriptorProperty, 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 DescriptorProperty, 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 DescriptorProperty, MapperProperty):

Method	`__getattr__`	Undocumented
Method	`_fallback_getattr`	Undocumented

def __init__(self, class_, *attrs, **kwargs):

overrides sqlalchemy.orm.interfaces.MapperProperty.__init__

Return a composite column-based property for use with a Mapper.

See the mapping documentation section :ref:`mapper_composite` for a full usage example.

The .MapperProperty returned by .composite is the .CompositeProperty.

Parameters
class_	The "composite type" class, or any classmethod or callable which will produce a new instance of the composite object given the column values in order.
*attrs	Undocumented
**kwargs	Undocumented
cols	List of Column objects to be mapped.
active_history=False	When `True`, indicates that the "previous" value for a scalar attribute should be loaded when replaced, if not already loaded. See the same flag on `.column_property`.
group	A group name for this property when marked as deferred.
deferred	When True, the column property is "deferred", meaning that it does not load immediately, and is instead loaded when the attribute is first accessed on an instance. See also `~sqlalchemy.orm.deferred`.
comparator_factory	a class which extends `.CompositeProperty.Comparator` which provides custom SQL clause generation for comparison operations.
doc	optional string that will be applied as the doc on the class-bound descriptor.
info	Optional data dictionary which will be populated into the `.MapperProperty.info` attribute of this object.

def __str__(self):

Undocumented

def _comparator_factory(self, mapper):

Undocumented

def _create_descriptor(self):

Create the Python descriptor that will serve as the access point on instances of the mapped class.

def _setup_arguments_on_columns(self):

Propagate configuration arguments made on this composite to the target columns, for those that apply.

def _setup_event_handlers(self):

Establish events that populate/expire the composite attribute.

def do_init(self):

overrides sqlalchemy.orm.interfaces.MapperProperty.do_init

Initialization which occurs after the .CompositeProperty has been associated with its parent mapper.

def get_history(self, state, dict_, passive=attributes.PASSIVE_OFF):

Provided for userland code that uses attributes.get_history().

def instrument_class(self, mapper):

overrides sqlalchemy.orm.descriptor_props.DescriptorProperty.instrument_class

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).

_COMPOSITE_FGET =

Undocumented

Value

object()

active_history =

Undocumented

attrs =

Undocumented

comparator_factory =

Undocumented

composite_class =

Undocumented

deferred =

Undocumented

descriptor =

overrides sqlalchemy.orm.descriptor_props.DescriptorProperty.descriptor

Undocumented

group =

Undocumented

info =

Undocumented

@util.memoized_property
_attribute_keys =

Undocumented

@util.memoized_property
_comparable_elements =

Undocumented

@property
columns =

Undocumented

@util.memoized_property
props =

Undocumented