sqlalchemy.orm.loading

module documentation

private module containing functions used to convert database rows into object instances and associated state.

the functions here are called primarily by Query, Mapper, as well as some of the attribute loading strategies.

Class	`PostLoad`	Track loaders and states for "post load" operations.
Function	`_decorate_polymorphic_switch`	Undocumented
Function	`_instance_processor`	Produce a mapper level row processor callable which processes rows into mapped instances.
Function	`_load_subclass_via_in`	Undocumented
Function	`_populate_full`	Undocumented
Function	`_populate_partial`	Undocumented
Function	`_set_get_options`	Undocumented
Function	`_setup_entity_query`	Undocumented
Function	`_validate_version_id`	Undocumented
Function	`_warn_for_runid_changed`	Undocumented
Function	`get_from_identity`	Look up the given key in the given session's identity map, check the object for expired state if found.
Function	`instances`	Return a `.Result` given an ORM query context.
Function	`load_on_ident`	Load the given identity key from the database.
Function	`load_on_pk_identity`	Load the given primary key identity from the database.
Function	`load_scalar_attributes`	initiate a column-based attribute refresh operation.
Function	`merge_frozen_result`	Merge a `_engine.FrozenResult` back into a `_orm.Session`, returning a new `_engine.Result` object with :term:`persistent` objects.
Function	`merge_result`	Merge a result into the given `.Query` object's Session.
Variable	`_new_runid`	Undocumented

def _decorate_polymorphic_switch(instance_fn, context, query_entity, mapper, result, path, polymorphic_discriminator, adapter, ensure_no_pk):

Undocumented

def _instance_processor(query_entity, mapper, context, result, path, adapter, only_load_props=None, refresh_state=None, polymorphic_discriminator=None, _polymorphic_from=None):

Produce a mapper level row processor callable which processes rows into mapped instances.

def _load_subclass_via_in(context, path, entity):

Undocumented

def _populate_full(context, row, state, dict_, isnew, load_path, loaded_instance, populate_existing, populators):

Undocumented

def _populate_partial(context, row, state, dict_, isnew, load_path, unloaded, populators):

Undocumented

def _set_get_options(compile_opt, load_opt, populate_existing=None, version_check=None, only_load_props=None, refresh_state=None, identity_token=None):

Undocumented

def _setup_entity_query(compile_state, mapper, query_entity, path, adapter, column_collection, with_polymorphic=None, only_load_props=None, polymorphic_discriminator=None, **kw):

Undocumented

def _validate_version_id(mapper, state, dict_, row, getter):

Undocumented

def _warn_for_runid_changed(state):

Undocumented

def get_from_identity(session, mapper, key, passive):

Look up the given key in the given session's identity map, check the object for expired state if found.

def instances(cursor, context):

Return a .Result given an ORM query context.

Changed in version 1.4: The instances() function now uses .Result objects and has an all new interface.

Parameters
cursor	a `.CursorResult`, generated by a statement which came from `.ORMCompileState`
context	a `.QueryContext` object
Returns
a `.Result` object representing ORM results

def load_on_ident(session, statement, key, load_options=None, refresh_state=None, with_for_update=None, only_load_props=None, no_autoflush=False, bind_arguments=util.EMPTY_DICT, execution_options=util.EMPTY_DICT):

Load the given identity key from the database.

def load_on_pk_identity(session, statement, primary_key_identity, load_options=None, refresh_state=None, with_for_update=None, only_load_props=None, identity_token=None, no_autoflush=False, bind_arguments=util.EMPTY_DICT, execution_options=util.EMPTY_DICT):

Load the given primary key identity from the database.

def load_scalar_attributes(mapper, state, attribute_names, passive):

initiate a column-based attribute refresh operation.

@util.preload_module('sqlalchemy.orm.context')
def merge_frozen_result(session, statement, frozen_result, load=True):

Merge a _engine.FrozenResult back into a _orm.Session, returning a new _engine.Result object with :term:`persistent` objects.

See the section :ref:`do_orm_execute_re_executing` for an example.