sqlalchemy.orm.properties.SynonymProperty

class documentation

class SynonymProperty(DescriptorProperty):

Undocumented

Method	`__init__`	Denote an attribute name as a synonym to a mapped property, in that the attribute will mirror the value and expression behavior of another attribute.
Method	`_comparator_factory`	Undocumented
Method	`get_history`	Undocumented
Method	`set_parent`	Set the parent mapper that references this MapperProperty.
Instance Variable	`comparator_factory`	Undocumented
Instance Variable	`descriptor`	Undocumented
Instance Variable	`doc`	Undocumented
Instance Variable	`info`	Undocumented
Instance Variable	`map_column`	Undocumented
Instance Variable	`name`	Undocumented
Instance Variable	`parent`	Undocumented
Property	`_proxied_object`	Undocumented
Property	`uses_objects`	Undocumented

Inherited from DescriptorProperty:

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.

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	`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	`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
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, name, map_column=None, descriptor=None, comparator_factory=None, doc=None, info=None):

overrides sqlalchemy.orm.interfaces.MapperProperty.__init__

Denote an attribute name as a synonym to a mapped property, in that the attribute will mirror the value and expression behavior of another attribute.

e.g.:

class MyClass(Base):
    __tablename__ = 'my_table'

    id = Column(Integer, primary_key=True)
    job_status = Column(String(50))

    status = synonym("job_status")

See Also

:ref:`synonyms` - Overview of synonyms

.synonym_for - a helper oriented towards Declarative

:ref:`mapper_hybrids` - The Hybrid Attribute extension provides an updated approach to augmenting attribute behavior more flexibly than can be achieved with synonyms.

Parameters
name	the name of the existing mapped property. This can refer to the string name ORM-mapped attribute configured on the class, including column-bound attributes and relationships.
map_column	For classical mappings and mappings against an existing Table object only. if `True`, the `.synonym` construct will locate the `_schema.Column` object upon the mapped table that would normally be associated with the attribute name of this synonym, and produce a new `.ColumnProperty` that instead maps this `_schema.Column` to the alternate name given as the "name" argument of the synonym; in this way, the usual step of redefining the mapping of the `_schema.Column` to be under a different name is unnecessary. This is usually intended to be used when a `_schema.Column` is to be replaced with an attribute that also uses a descriptor, that is, in conjunction with the :paramref:`.synonym.descriptor` parameter: my_table = Table( "my_table", metadata, Column('id', Integer, primary_key=True), Column('job_status', String(50)) ) class MyClass(object): @property def _job_status_descriptor(self): return "Status: %s" % self._job_status mapper( MyClass, my_table, properties={ "job_status": synonym( "_job_status", map_column=True, descriptor=MyClass._job_status_descriptor) } ) Above, the attribute named `_job_status` is automatically mapped to the `job_status` column: >>> j1 = MyClass() >>> j1._job_status = "employed" >>> j1.job_status Status: employed When using Declarative, in order to provide a descriptor in conjunction with a synonym, use the `sqlalchemy.ext.declarative.synonym_for` helper. However, note that the :ref:`hybrid properties <mapper_hybrids>` feature should usually be preferred, particularly when redefining attribute behavior.
descriptor	a Python :term:`descriptor` that will be used as a getter (and potentially a setter) when this attribute is accessed at the instance level.
comparator_factory	A subclass of `.PropComparator` that will provide custom comparison behavior at the SQL expression level. Note For the use case of providing an attribute which redefines both Python-level and SQL-expression level behavior of an attribute, please refer to the Hybrid attribute introduced at :ref:`mapper_hybrids` for a more effective technique.
doc	Undocumented
info	Optional data dictionary which will be populated into the `.InspectionAttr.info` attribute of this object. New in version 1.0.0.

def _comparator_factory(self, mapper):

Undocumented

def get_history(self, *arg, **kw):

Undocumented

@util.preload_module('sqlalchemy.orm.properties')
def set_parent(self, parent, init):

overrides sqlalchemy.orm.interfaces.MapperProperty.set_parent

Set the parent mapper that references this MapperProperty.

This method is overridden by some subclasses to perform extra setup when the mapper is first known.

comparator_factory =

Undocumented

descriptor =

overrides sqlalchemy.orm.descriptor_props.DescriptorProperty.descriptor

Undocumented

doc =

overrides sqlalchemy.orm.descriptor_props.DescriptorProperty.doc

Undocumented

info =

Undocumented

map_column =

Undocumented

name =

Undocumented

parent =

overrides sqlalchemy.orm.interfaces.MapperProperty.parent

Undocumented

@util.memoized_property
_proxied_object =

Undocumented

@property
uses_objects =

overrides sqlalchemy.orm.descriptor_props.DescriptorProperty.uses_objects

Undocumented