sqlalchemy.orm.dependency.DetectKeySwitch

class documentation

class DetectKeySwitch(DependencyProcessor):

For many-to-one relationships with no one-to-many backref, searches for parents through the unit of work when a primary key has changed and updates them.

Theoretically, this approach could be expanded to support transparent deletion of objects referenced via many-to-one as well, although the current attribute system doesn't do enough bookkeeping for this to be efficient.

Method	`_key_switchers`	Undocumented
Method	`_pks_changed`	Undocumented
Method	`_process_key_switches`	Undocumented
Method	`per_property_flush_actions`	Undocumented
Method	`per_property_preprocessors`	establish actions and dependencies related to a flush.
Method	`per_state_flush_actions`	establish actions and dependencies related to a flush.
Method	`presort_deletes`	Undocumented
Method	`presort_saves`	Undocumented
Method	`process_deletes`	Undocumented
Method	`process_saves`	Undocumented
Method	`prop_has_changes`	Undocumented

Inherited from DependencyProcessor:

Class Method	`from_relationship`	Undocumented
Method	`__init__`	Undocumented
Method	`__repr__`	Undocumented
Method	`_get_reversed_processed_set`	Undocumented
Method	`_post_update`	Undocumented
Method	`_synchronize`	Undocumented
Method	`_verify_canload`	Undocumented
Method	`hasparent`	return True if the given object instance has a parent, according to the `InstrumentedAttribute` handled by this `DependencyProcessor`.
Instance Variable	`_passive_delete_flag`	Undocumented
Instance Variable	`_passive_update_flag`	Undocumented
Instance Variable	`cascade`	Undocumented
Instance Variable	`direction`	Undocumented
Instance Variable	`enable_typechecks`	Undocumented
Instance Variable	`key`	Undocumented
Instance Variable	`mapper`	Undocumented
Instance Variable	`parent`	Undocumented
Instance Variable	`passive_deletes`	Undocumented
Instance Variable	`passive_updates`	Undocumented
Instance Variable	`post_update`	Undocumented
Instance Variable	`prop`	Undocumented
Instance Variable	`secondary`	Undocumented
Instance Variable	`sort_key`	Undocumented

def _key_switchers(self, uow, states):

Undocumented

def _pks_changed(self, uowcommit, state):

overrides sqlalchemy.orm.dependency.DependencyProcessor._pks_changed

Undocumented

def _process_key_switches(self, deplist, uowcommit):

Undocumented

def per_property_flush_actions(self, uow):

overrides sqlalchemy.orm.dependency.DependencyProcessor.per_property_flush_actions

Undocumented

def per_property_preprocessors(self, uow):

overrides sqlalchemy.orm.dependency.DependencyProcessor.per_property_preprocessors

establish actions and dependencies related to a flush.

These actions will operate on all relevant states in the aggregate.

def per_state_flush_actions(self, uow, states, isdelete):

overrides sqlalchemy.orm.dependency.DependencyProcessor.per_state_flush_actions

establish actions and dependencies related to a flush.

These actions will operate on all relevant states individually. This occurs only if there are cycles in the 'aggregated' version of events.

def presort_deletes(self, uowcommit, states):

overrides sqlalchemy.orm.dependency.DependencyProcessor.presort_deletes

Undocumented

def presort_saves(self, uow, states):

overrides sqlalchemy.orm.dependency.DependencyProcessor.presort_saves

Undocumented

def process_deletes(self, uowcommit, states):

overrides sqlalchemy.orm.dependency.DependencyProcessor.process_deletes

Undocumented

def process_saves(self, uowcommit, states):

overrides sqlalchemy.orm.dependency.DependencyProcessor.process_saves

Undocumented

def prop_has_changes(self, uow, states, isdelete):

overrides sqlalchemy.orm.dependency.DependencyProcessor.prop_has_changes

Undocumented