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1323 lines
50 KiB
Python
1323 lines
50 KiB
Python
# orm/properties.py
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# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""MapperProperty implementations.
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This is a private module which defines the behavior of invidual ORM-
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mapped attributes.
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"""
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from .. import sql, util, log, exc as sa_exc, inspect
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from ..sql import operators, expression
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from . import (
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attributes, mapper,
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strategies, configure_mappers, relationships,
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dependency
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)
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from .util import CascadeOptions, \
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_orm_annotate, _orm_deannotate, _orm_full_deannotate
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from .interfaces import MANYTOMANY, MANYTOONE, ONETOMANY,\
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PropComparator, StrategizedProperty
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mapperlib = util.importlater("sqlalchemy.orm", "mapperlib")
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NoneType = type(None)
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from descriptor_props import CompositeProperty, SynonymProperty, \
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ComparableProperty, ConcreteInheritedProperty
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__all__ = ['ColumnProperty', 'CompositeProperty', 'SynonymProperty',
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'ComparableProperty', 'RelationshipProperty', 'RelationProperty']
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class ColumnProperty(StrategizedProperty):
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"""Describes an object attribute that corresponds to a table column.
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Public constructor is the :func:`.orm.column_property` function.
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"""
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def __init__(self, *columns, **kwargs):
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"""Construct a ColumnProperty.
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Note the public constructor is the :func:`.orm.column_property`
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function.
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:param \*columns: The list of `columns` describes a single
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object property. If there are multiple tables joined
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together for the mapper, this list represents the equivalent
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column as it appears across each table.
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:param group:
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:param deferred:
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:param comparator_factory:
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:param descriptor:
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:param expire_on_flush:
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:param extension:
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:param info: Optional data dictionary which will be populated into the
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:attr:`.info` attribute of this object.
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"""
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self._orig_columns = [expression._labeled(c) for c in columns]
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self.columns = [expression._labeled(_orm_full_deannotate(c))
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for c in columns]
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self.group = kwargs.pop('group', None)
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self.deferred = kwargs.pop('deferred', False)
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self.instrument = kwargs.pop('_instrument', True)
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self.comparator_factory = kwargs.pop('comparator_factory',
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self.__class__.Comparator)
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self.descriptor = kwargs.pop('descriptor', None)
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self.extension = kwargs.pop('extension', None)
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self.active_history = kwargs.pop('active_history', False)
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self.expire_on_flush = kwargs.pop('expire_on_flush', True)
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if 'info' in kwargs:
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self.info = kwargs.pop('info')
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if 'doc' in kwargs:
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self.doc = kwargs.pop('doc')
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else:
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for col in reversed(self.columns):
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doc = getattr(col, 'doc', None)
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if doc is not None:
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self.doc = doc
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break
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else:
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self.doc = None
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if kwargs:
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raise TypeError(
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"%s received unexpected keyword argument(s): %s" % (
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self.__class__.__name__,
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', '.join(sorted(kwargs.keys()))))
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util.set_creation_order(self)
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if not self.instrument:
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self.strategy_class = strategies.UninstrumentedColumnLoader
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elif self.deferred:
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self.strategy_class = strategies.DeferredColumnLoader
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else:
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self.strategy_class = strategies.ColumnLoader
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@property
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def expression(self):
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"""Return the primary column or expression for this ColumnProperty.
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"""
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return self.columns[0]
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def instrument_class(self, mapper):
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if not self.instrument:
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return
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attributes.register_descriptor(
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mapper.class_,
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self.key,
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comparator=self.comparator_factory(self, mapper),
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parententity=mapper,
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doc=self.doc
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)
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def do_init(self):
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super(ColumnProperty, self).do_init()
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if len(self.columns) > 1 and \
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set(self.parent.primary_key).issuperset(self.columns):
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util.warn(
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("On mapper %s, primary key column '%s' is being combined "
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"with distinct primary key column '%s' in attribute '%s'. "
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"Use explicit properties to give each column its own mapped "
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"attribute name.") % (self.parent, self.columns[1],
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self.columns[0], self.key))
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def copy(self):
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return ColumnProperty(
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deferred=self.deferred,
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group=self.group,
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active_history=self.active_history,
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*self.columns)
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def _getcommitted(self, state, dict_, column,
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passive=attributes.PASSIVE_OFF):
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return state.get_impl(self.key).\
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get_committed_value(state, dict_, passive=passive)
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def merge(self, session, source_state, source_dict, dest_state,
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dest_dict, load, _recursive):
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if not self.instrument:
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return
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elif self.key in source_dict:
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value = source_dict[self.key]
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if not load:
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dest_dict[self.key] = value
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else:
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impl = dest_state.get_impl(self.key)
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impl.set(dest_state, dest_dict, value, None)
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elif dest_state.has_identity and self.key not in dest_dict:
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dest_state._expire_attributes(dest_dict, [self.key])
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class Comparator(PropComparator):
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"""Produce boolean, comparison, and other operators for
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:class:`.ColumnProperty` attributes.
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See the documentation for :class:`.PropComparator` for a brief
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overview.
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See also:
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:class:`.PropComparator`
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:class:`.ColumnOperators`
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:ref:`types_operators`
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:attr:`.TypeEngine.comparator_factory`
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"""
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@util.memoized_instancemethod
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def __clause_element__(self):
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if self.adapter:
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return self.adapter(self.prop.columns[0])
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else:
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return self.prop.columns[0]._annotate({
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"parententity": self._parentmapper,
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"parentmapper": self._parentmapper})
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@util.memoized_property
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def info(self):
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ce = self.__clause_element__()
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try:
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return ce.info
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except AttributeError:
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return self.prop.info
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def __getattr__(self, key):
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"""proxy attribute access down to the mapped column.
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this allows user-defined comparison methods to be accessed.
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"""
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return getattr(self.__clause_element__(), key)
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def operate(self, op, *other, **kwargs):
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return op(self.__clause_element__(), *other, **kwargs)
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def reverse_operate(self, op, other, **kwargs):
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col = self.__clause_element__()
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return op(col._bind_param(op, other), col, **kwargs)
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# TODO: legacy..do we need this ? (0.5)
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ColumnComparator = Comparator
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def __str__(self):
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return str(self.parent.class_.__name__) + "." + self.key
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log.class_logger(ColumnProperty)
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class RelationshipProperty(StrategizedProperty):
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"""Describes an object property that holds a single item or list
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of items that correspond to a related database table.
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Public constructor is the :func:`.orm.relationship` function.
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See also:
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:ref:`relationship_config_toplevel`
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"""
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strategy_wildcard_key = 'relationship:*'
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_dependency_processor = None
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def __init__(self, argument,
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secondary=None, primaryjoin=None,
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secondaryjoin=None,
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foreign_keys=None,
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uselist=None,
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order_by=False,
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backref=None,
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back_populates=None,
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post_update=False,
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cascade=False, extension=None,
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viewonly=False, lazy=True,
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collection_class=None, passive_deletes=False,
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passive_updates=True, remote_side=None,
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enable_typechecks=True, join_depth=None,
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comparator_factory=None,
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single_parent=False, innerjoin=False,
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distinct_target_key=False,
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doc=None,
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active_history=False,
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cascade_backrefs=True,
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load_on_pending=False,
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strategy_class=None, _local_remote_pairs=None,
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query_class=None,
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info=None):
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self.uselist = uselist
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self.argument = argument
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self.secondary = secondary
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self.primaryjoin = primaryjoin
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self.secondaryjoin = secondaryjoin
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self.post_update = post_update
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self.direction = None
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self.viewonly = viewonly
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self.lazy = lazy
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self.single_parent = single_parent
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self._user_defined_foreign_keys = foreign_keys
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self.collection_class = collection_class
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self.passive_deletes = passive_deletes
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self.cascade_backrefs = cascade_backrefs
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self.passive_updates = passive_updates
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self.remote_side = remote_side
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self.enable_typechecks = enable_typechecks
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self.query_class = query_class
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self.innerjoin = innerjoin
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self.distinct_target_key = distinct_target_key
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self.doc = doc
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self.active_history = active_history
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self.join_depth = join_depth
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self.local_remote_pairs = _local_remote_pairs
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self.extension = extension
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self.load_on_pending = load_on_pending
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self.comparator_factory = comparator_factory or \
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RelationshipProperty.Comparator
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self.comparator = self.comparator_factory(self, None)
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util.set_creation_order(self)
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if info is not None:
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self.info = info
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if strategy_class:
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self.strategy_class = strategy_class
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elif self.lazy == 'dynamic':
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from sqlalchemy.orm import dynamic
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self.strategy_class = dynamic.DynaLoader
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else:
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self.strategy_class = strategies.factory(self.lazy)
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self._reverse_property = set()
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self.cascade = cascade if cascade is not False \
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else "save-update, merge"
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self.order_by = order_by
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self.back_populates = back_populates
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if self.back_populates:
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if backref:
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raise sa_exc.ArgumentError(
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"backref and back_populates keyword arguments "
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"are mutually exclusive")
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self.backref = None
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else:
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self.backref = backref
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def instrument_class(self, mapper):
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attributes.register_descriptor(
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mapper.class_,
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self.key,
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comparator=self.comparator_factory(self, mapper),
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parententity=mapper,
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doc=self.doc,
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)
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class Comparator(PropComparator):
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"""Produce boolean, comparison, and other operators for
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:class:`.RelationshipProperty` attributes.
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See the documentation for :class:`.PropComparator` for a brief overview
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of ORM level operator definition.
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See also:
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:class:`.PropComparator`
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:class:`.ColumnProperty.Comparator`
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:class:`.ColumnOperators`
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:ref:`types_operators`
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:attr:`.TypeEngine.comparator_factory`
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"""
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_of_type = None
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def __init__(self, prop, parentmapper, of_type=None, adapter=None):
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"""Construction of :class:`.RelationshipProperty.Comparator`
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is internal to the ORM's attribute mechanics.
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"""
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self.prop = prop
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self._parentmapper = parentmapper
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self.adapter = adapter
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if of_type:
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self._of_type = of_type
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def adapted(self, adapter):
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"""Return a copy of this PropComparator which will use the
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given adaption function on the local side of generated
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expressions.
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"""
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return self.__class__(self.property, self._parentmapper,
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getattr(self, '_of_type', None),
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adapter)
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@util.memoized_property
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def mapper(self):
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"""The target :class:`.Mapper` referred to by this
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:class:`.RelationshipProperty.Comparator.
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This is the "target" or "remote" side of the
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:func:`.relationship`.
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"""
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return self.property.mapper
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@util.memoized_property
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def _parententity(self):
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return self.property.parent
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def _source_selectable(self):
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elem = self.property.parent._with_polymorphic_selectable
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if self.adapter:
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return self.adapter(elem)
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else:
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return elem
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def __clause_element__(self):
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adapt_from = self._source_selectable()
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if self._of_type:
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of_type = inspect(self._of_type).mapper
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else:
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of_type = None
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pj, sj, source, dest, \
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secondary, target_adapter = self.property._create_joins(
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source_selectable=adapt_from,
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source_polymorphic=True,
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of_type=of_type)
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if sj is not None:
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return pj & sj
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else:
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return pj
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def of_type(self, cls):
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"""Produce a construct that represents a particular 'subtype' of
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attribute for the parent class.
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Currently this is usable in conjunction with :meth:`.Query.join`
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and :meth:`.Query.outerjoin`.
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"""
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return RelationshipProperty.Comparator(
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self.property,
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self._parentmapper,
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cls, adapter=self.adapter)
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def in_(self, other):
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"""Produce an IN clause - this is not implemented
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for :func:`~.orm.relationship`-based attributes at this time.
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"""
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raise NotImplementedError('in_() not yet supported for '
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'relationships. For a simple many-to-one, use '
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'in_() against the set of foreign key values.')
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__hash__ = None
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def __eq__(self, other):
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"""Implement the ``==`` operator.
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In a many-to-one context, such as::
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MyClass.some_prop == <some object>
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this will typically produce a
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clause such as::
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mytable.related_id == <some id>
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Where ``<some id>`` is the primary key of the given
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object.
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The ``==`` operator provides partial functionality for non-
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many-to-one comparisons:
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* Comparisons against collections are not supported.
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Use :meth:`~.RelationshipProperty.Comparator.contains`.
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* Compared to a scalar one-to-many, will produce a
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clause that compares the target columns in the parent to
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the given target.
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* Compared to a scalar many-to-many, an alias
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of the association table will be rendered as
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well, forming a natural join that is part of the
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main body of the query. This will not work for
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queries that go beyond simple AND conjunctions of
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comparisons, such as those which use OR. Use
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explicit joins, outerjoins, or
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:meth:`~.RelationshipProperty.Comparator.has` for
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more comprehensive non-many-to-one scalar
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membership tests.
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* Comparisons against ``None`` given in a one-to-many
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or many-to-many context produce a NOT EXISTS clause.
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"""
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if isinstance(other, (NoneType, expression.Null)):
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if self.property.direction in [ONETOMANY, MANYTOMANY]:
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return ~self._criterion_exists()
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else:
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return _orm_annotate(self.property._optimized_compare(
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None, adapt_source=self.adapter))
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elif self.property.uselist:
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raise sa_exc.InvalidRequestError("Can't compare a colle"
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"ction to an object or collection; use "
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"contains() to test for membership.")
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else:
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return _orm_annotate(self.property._optimized_compare(other,
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adapt_source=self.adapter))
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|
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def _criterion_exists(self, criterion=None, **kwargs):
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if getattr(self, '_of_type', None):
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info = inspect(self._of_type)
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target_mapper, to_selectable, is_aliased_class = \
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info.mapper, info.selectable, info.is_aliased_class
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if self.property._is_self_referential and not is_aliased_class:
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to_selectable = to_selectable.alias()
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single_crit = target_mapper._single_table_criterion
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if single_crit is not None:
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if criterion is not None:
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criterion = single_crit & criterion
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else:
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criterion = single_crit
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else:
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is_aliased_class = False
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to_selectable = None
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if self.adapter:
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source_selectable = self._source_selectable()
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else:
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source_selectable = None
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pj, sj, source, dest, secondary, target_adapter = \
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self.property._create_joins(dest_polymorphic=True,
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dest_selectable=to_selectable,
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source_selectable=source_selectable)
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for k in kwargs:
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crit = getattr(self.property.mapper.class_, k) == kwargs[k]
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if criterion is None:
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criterion = crit
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else:
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criterion = criterion & crit
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# annotate the *local* side of the join condition, in the case
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# of pj + sj this is the full primaryjoin, in the case of just
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# pj its the local side of the primaryjoin.
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if sj is not None:
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j = _orm_annotate(pj) & sj
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else:
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j = _orm_annotate(pj, exclude=self.property.remote_side)
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if criterion is not None and target_adapter and not is_aliased_class:
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# limit this adapter to annotated only?
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criterion = target_adapter.traverse(criterion)
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|
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# only have the "joined left side" of what we
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# return be subject to Query adaption. The right
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# side of it is used for an exists() subquery and
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# should not correlate or otherwise reach out
|
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# to anything in the enclosing query.
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|
if criterion is not None:
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criterion = criterion._annotate(
|
|
{'no_replacement_traverse': True})
|
|
|
|
crit = j & criterion
|
|
|
|
ex = sql.exists([1], crit, from_obj=dest).correlate_except(dest)
|
|
if secondary is not None:
|
|
ex = ex.correlate_except(secondary)
|
|
return ex
|
|
|
|
def any(self, criterion=None, **kwargs):
|
|
"""Produce an expression that tests a collection against
|
|
particular criterion, using EXISTS.
|
|
|
|
An expression like::
|
|
|
|
session.query(MyClass).filter(
|
|
MyClass.somereference.any(SomeRelated.x==2)
|
|
)
|
|
|
|
|
|
Will produce a query like::
|
|
|
|
SELECT * FROM my_table WHERE
|
|
EXISTS (SELECT 1 FROM related WHERE related.my_id=my_table.id
|
|
AND related.x=2)
|
|
|
|
Because :meth:`~.RelationshipProperty.Comparator.any` uses
|
|
a correlated subquery, its performance is not nearly as
|
|
good when compared against large target tables as that of
|
|
using a join.
|
|
|
|
:meth:`~.RelationshipProperty.Comparator.any` is particularly
|
|
useful for testing for empty collections::
|
|
|
|
session.query(MyClass).filter(
|
|
~MyClass.somereference.any()
|
|
)
|
|
|
|
will produce::
|
|
|
|
SELECT * FROM my_table WHERE
|
|
NOT EXISTS (SELECT 1 FROM related WHERE
|
|
related.my_id=my_table.id)
|
|
|
|
:meth:`~.RelationshipProperty.Comparator.any` is only
|
|
valid for collections, i.e. a :func:`.relationship`
|
|
that has ``uselist=True``. For scalar references,
|
|
use :meth:`~.RelationshipProperty.Comparator.has`.
|
|
|
|
"""
|
|
if not self.property.uselist:
|
|
raise sa_exc.InvalidRequestError(
|
|
"'any()' not implemented for scalar "
|
|
"attributes. Use has()."
|
|
)
|
|
|
|
return self._criterion_exists(criterion, **kwargs)
|
|
|
|
def has(self, criterion=None, **kwargs):
|
|
"""Produce an expression that tests a scalar reference against
|
|
particular criterion, using EXISTS.
|
|
|
|
An expression like::
|
|
|
|
session.query(MyClass).filter(
|
|
MyClass.somereference.has(SomeRelated.x==2)
|
|
)
|
|
|
|
|
|
Will produce a query like::
|
|
|
|
SELECT * FROM my_table WHERE
|
|
EXISTS (SELECT 1 FROM related WHERE
|
|
related.id==my_table.related_id AND related.x=2)
|
|
|
|
Because :meth:`~.RelationshipProperty.Comparator.has` uses
|
|
a correlated subquery, its performance is not nearly as
|
|
good when compared against large target tables as that of
|
|
using a join.
|
|
|
|
:meth:`~.RelationshipProperty.Comparator.has` is only
|
|
valid for scalar references, i.e. a :func:`.relationship`
|
|
that has ``uselist=False``. For collection references,
|
|
use :meth:`~.RelationshipProperty.Comparator.any`.
|
|
|
|
"""
|
|
if self.property.uselist:
|
|
raise sa_exc.InvalidRequestError(
|
|
"'has()' not implemented for collections. "
|
|
"Use any().")
|
|
return self._criterion_exists(criterion, **kwargs)
|
|
|
|
def contains(self, other, **kwargs):
|
|
"""Return a simple expression that tests a collection for
|
|
containment of a particular item.
|
|
|
|
:meth:`~.RelationshipProperty.Comparator.contains` is
|
|
only valid for a collection, i.e. a
|
|
:func:`~.orm.relationship` that implements
|
|
one-to-many or many-to-many with ``uselist=True``.
|
|
|
|
When used in a simple one-to-many context, an
|
|
expression like::
|
|
|
|
MyClass.contains(other)
|
|
|
|
Produces a clause like::
|
|
|
|
mytable.id == <some id>
|
|
|
|
Where ``<some id>`` is the value of the foreign key
|
|
attribute on ``other`` which refers to the primary
|
|
key of its parent object. From this it follows that
|
|
:meth:`~.RelationshipProperty.Comparator.contains` is
|
|
very useful when used with simple one-to-many
|
|
operations.
|
|
|
|
For many-to-many operations, the behavior of
|
|
:meth:`~.RelationshipProperty.Comparator.contains`
|
|
has more caveats. The association table will be
|
|
rendered in the statement, producing an "implicit"
|
|
join, that is, includes multiple tables in the FROM
|
|
clause which are equated in the WHERE clause::
|
|
|
|
query(MyClass).filter(MyClass.contains(other))
|
|
|
|
Produces a query like::
|
|
|
|
SELECT * FROM my_table, my_association_table AS
|
|
my_association_table_1 WHERE
|
|
my_table.id = my_association_table_1.parent_id
|
|
AND my_association_table_1.child_id = <some id>
|
|
|
|
Where ``<some id>`` would be the primary key of
|
|
``other``. From the above, it is clear that
|
|
:meth:`~.RelationshipProperty.Comparator.contains`
|
|
will **not** work with many-to-many collections when
|
|
used in queries that move beyond simple AND
|
|
conjunctions, such as multiple
|
|
:meth:`~.RelationshipProperty.Comparator.contains`
|
|
expressions joined by OR. In such cases subqueries or
|
|
explicit "outer joins" will need to be used instead.
|
|
See :meth:`~.RelationshipProperty.Comparator.any` for
|
|
a less-performant alternative using EXISTS, or refer
|
|
to :meth:`.Query.outerjoin` as well as :ref:`ormtutorial_joins`
|
|
for more details on constructing outer joins.
|
|
|
|
"""
|
|
if not self.property.uselist:
|
|
raise sa_exc.InvalidRequestError(
|
|
"'contains' not implemented for scalar "
|
|
"attributes. Use ==")
|
|
clause = self.property._optimized_compare(other,
|
|
adapt_source=self.adapter)
|
|
|
|
if self.property.secondaryjoin is not None:
|
|
clause.negation_clause = \
|
|
self.__negated_contains_or_equals(other)
|
|
|
|
return clause
|
|
|
|
def __negated_contains_or_equals(self, other):
|
|
if self.property.direction == MANYTOONE:
|
|
state = attributes.instance_state(other)
|
|
|
|
def state_bindparam(x, state, col):
|
|
o = state.obj() # strong ref
|
|
return sql.bindparam(x, unique=True, callable_=lambda: \
|
|
self.property.mapper._get_committed_attr_by_column(o, col))
|
|
|
|
def adapt(col):
|
|
if self.adapter:
|
|
return self.adapter(col)
|
|
else:
|
|
return col
|
|
|
|
if self.property._use_get:
|
|
return sql.and_(*[
|
|
sql.or_(
|
|
adapt(x) != state_bindparam(adapt(x), state, y),
|
|
adapt(x) == None)
|
|
for (x, y) in self.property.local_remote_pairs])
|
|
|
|
criterion = sql.and_(*[x == y for (x, y) in
|
|
zip(
|
|
self.property.mapper.primary_key,
|
|
self.property.\
|
|
mapper.\
|
|
primary_key_from_instance(other))
|
|
])
|
|
return ~self._criterion_exists(criterion)
|
|
|
|
def __ne__(self, other):
|
|
"""Implement the ``!=`` operator.
|
|
|
|
In a many-to-one context, such as::
|
|
|
|
MyClass.some_prop != <some object>
|
|
|
|
This will typically produce a clause such as::
|
|
|
|
mytable.related_id != <some id>
|
|
|
|
Where ``<some id>`` is the primary key of the
|
|
given object.
|
|
|
|
The ``!=`` operator provides partial functionality for non-
|
|
many-to-one comparisons:
|
|
|
|
* Comparisons against collections are not supported.
|
|
Use
|
|
:meth:`~.RelationshipProperty.Comparator.contains`
|
|
in conjunction with :func:`~.expression.not_`.
|
|
* Compared to a scalar one-to-many, will produce a
|
|
clause that compares the target columns in the parent to
|
|
the given target.
|
|
* Compared to a scalar many-to-many, an alias
|
|
of the association table will be rendered as
|
|
well, forming a natural join that is part of the
|
|
main body of the query. This will not work for
|
|
queries that go beyond simple AND conjunctions of
|
|
comparisons, such as those which use OR. Use
|
|
explicit joins, outerjoins, or
|
|
:meth:`~.RelationshipProperty.Comparator.has` in
|
|
conjunction with :func:`~.expression.not_` for
|
|
more comprehensive non-many-to-one scalar
|
|
membership tests.
|
|
* Comparisons against ``None`` given in a one-to-many
|
|
or many-to-many context produce an EXISTS clause.
|
|
|
|
"""
|
|
if isinstance(other, (NoneType, expression.Null)):
|
|
if self.property.direction == MANYTOONE:
|
|
return sql.or_(*[x != None for x in
|
|
self.property._calculated_foreign_keys])
|
|
else:
|
|
return self._criterion_exists()
|
|
elif self.property.uselist:
|
|
raise sa_exc.InvalidRequestError("Can't compare a collection"
|
|
" to an object or collection; use "
|
|
"contains() to test for membership.")
|
|
else:
|
|
return self.__negated_contains_or_equals(other)
|
|
|
|
@util.memoized_property
|
|
def property(self):
|
|
if mapperlib.module._new_mappers:
|
|
configure_mappers()
|
|
return self.prop
|
|
|
|
def compare(self, op, value,
|
|
value_is_parent=False,
|
|
alias_secondary=True):
|
|
if op == operators.eq:
|
|
if value is None:
|
|
if self.uselist:
|
|
return ~sql.exists([1], self.primaryjoin)
|
|
else:
|
|
return self._optimized_compare(None,
|
|
value_is_parent=value_is_parent,
|
|
alias_secondary=alias_secondary)
|
|
else:
|
|
return self._optimized_compare(value,
|
|
value_is_parent=value_is_parent,
|
|
alias_secondary=alias_secondary)
|
|
else:
|
|
return op(self.comparator, value)
|
|
|
|
def _optimized_compare(self, value, value_is_parent=False,
|
|
adapt_source=None,
|
|
alias_secondary=True):
|
|
if value is not None:
|
|
value = attributes.instance_state(value)
|
|
return self._get_strategy(strategies.LazyLoader).lazy_clause(value,
|
|
reverse_direction=not value_is_parent,
|
|
alias_secondary=alias_secondary,
|
|
adapt_source=adapt_source)
|
|
|
|
def __str__(self):
|
|
return str(self.parent.class_.__name__) + "." + self.key
|
|
|
|
def merge(self,
|
|
session,
|
|
source_state,
|
|
source_dict,
|
|
dest_state,
|
|
dest_dict,
|
|
load, _recursive):
|
|
|
|
if load:
|
|
for r in self._reverse_property:
|
|
if (source_state, r) in _recursive:
|
|
return
|
|
|
|
if not "merge" in self._cascade:
|
|
return
|
|
|
|
if self.key not in source_dict:
|
|
return
|
|
|
|
if self.uselist:
|
|
instances = source_state.get_impl(self.key).\
|
|
get(source_state, source_dict)
|
|
if hasattr(instances, '_sa_adapter'):
|
|
# convert collections to adapters to get a true iterator
|
|
instances = instances._sa_adapter
|
|
|
|
if load:
|
|
# for a full merge, pre-load the destination collection,
|
|
# so that individual _merge of each item pulls from identity
|
|
# map for those already present.
|
|
# also assumes CollectionAttrbiuteImpl behavior of loading
|
|
# "old" list in any case
|
|
dest_state.get_impl(self.key).get(dest_state, dest_dict)
|
|
|
|
dest_list = []
|
|
for current in instances:
|
|
current_state = attributes.instance_state(current)
|
|
current_dict = attributes.instance_dict(current)
|
|
_recursive[(current_state, self)] = True
|
|
obj = session._merge(current_state, current_dict,
|
|
load=load, _recursive=_recursive)
|
|
if obj is not None:
|
|
dest_list.append(obj)
|
|
|
|
if not load:
|
|
coll = attributes.init_state_collection(dest_state,
|
|
dest_dict, self.key)
|
|
for c in dest_list:
|
|
coll.append_without_event(c)
|
|
else:
|
|
dest_state.get_impl(self.key)._set_iterable(dest_state,
|
|
dest_dict, dest_list)
|
|
else:
|
|
current = source_dict[self.key]
|
|
if current is not None:
|
|
current_state = attributes.instance_state(current)
|
|
current_dict = attributes.instance_dict(current)
|
|
_recursive[(current_state, self)] = True
|
|
obj = session._merge(current_state, current_dict,
|
|
load=load, _recursive=_recursive)
|
|
else:
|
|
obj = None
|
|
|
|
if not load:
|
|
dest_dict[self.key] = obj
|
|
else:
|
|
dest_state.get_impl(self.key).set(dest_state,
|
|
dest_dict, obj, None)
|
|
|
|
def _value_as_iterable(self, state, dict_, key,
|
|
passive=attributes.PASSIVE_OFF):
|
|
"""Return a list of tuples (state, obj) for the given
|
|
key.
|
|
|
|
returns an empty list if the value is None/empty/PASSIVE_NO_RESULT
|
|
"""
|
|
|
|
impl = state.manager[key].impl
|
|
x = impl.get(state, dict_, passive=passive)
|
|
if x is attributes.PASSIVE_NO_RESULT or x is None:
|
|
return []
|
|
elif hasattr(impl, 'get_collection'):
|
|
return [
|
|
(attributes.instance_state(o), o) for o in
|
|
impl.get_collection(state, dict_, x, passive=passive)
|
|
]
|
|
else:
|
|
return [(attributes.instance_state(x), x)]
|
|
|
|
def cascade_iterator(self, type_, state, dict_,
|
|
visited_states, halt_on=None):
|
|
#assert type_ in self._cascade
|
|
|
|
# only actively lazy load on the 'delete' cascade
|
|
if type_ != 'delete' or self.passive_deletes:
|
|
passive = attributes.PASSIVE_NO_INITIALIZE
|
|
else:
|
|
passive = attributes.PASSIVE_OFF
|
|
|
|
if type_ == 'save-update':
|
|
tuples = state.manager[self.key].impl.\
|
|
get_all_pending(state, dict_)
|
|
|
|
else:
|
|
tuples = self._value_as_iterable(state, dict_, self.key,
|
|
passive=passive)
|
|
|
|
skip_pending = type_ == 'refresh-expire' and 'delete-orphan' \
|
|
not in self._cascade
|
|
|
|
for instance_state, c in tuples:
|
|
if instance_state in visited_states:
|
|
continue
|
|
|
|
if c is None:
|
|
# would like to emit a warning here, but
|
|
# would not be consistent with collection.append(None)
|
|
# current behavior of silently skipping.
|
|
# see [ticket:2229]
|
|
continue
|
|
|
|
instance_dict = attributes.instance_dict(c)
|
|
|
|
if halt_on and halt_on(instance_state):
|
|
continue
|
|
|
|
if skip_pending and not instance_state.key:
|
|
continue
|
|
|
|
instance_mapper = instance_state.manager.mapper
|
|
|
|
if not instance_mapper.isa(self.mapper.class_manager.mapper):
|
|
raise AssertionError("Attribute '%s' on class '%s' "
|
|
"doesn't handle objects "
|
|
"of type '%s'" % (
|
|
self.key,
|
|
self.parent.class_,
|
|
c.__class__
|
|
))
|
|
|
|
visited_states.add(instance_state)
|
|
|
|
yield c, instance_mapper, instance_state, instance_dict
|
|
|
|
def _add_reverse_property(self, key):
|
|
other = self.mapper.get_property(key, _configure_mappers=False)
|
|
self._reverse_property.add(other)
|
|
other._reverse_property.add(self)
|
|
|
|
if not other.mapper.common_parent(self.parent):
|
|
raise sa_exc.ArgumentError('reverse_property %r on '
|
|
'relationship %s references relationship %s, which '
|
|
'does not reference mapper %s' % (key, self, other,
|
|
self.parent))
|
|
if self.direction in (ONETOMANY, MANYTOONE) and self.direction \
|
|
== other.direction:
|
|
raise sa_exc.ArgumentError('%s and back-reference %s are '
|
|
'both of the same direction %r. Did you mean to '
|
|
'set remote_side on the many-to-one side ?'
|
|
% (other, self, self.direction))
|
|
|
|
@util.memoized_property
|
|
def mapper(self):
|
|
"""Return the targeted :class:`.Mapper` for this
|
|
:class:`.RelationshipProperty`.
|
|
|
|
This is a lazy-initializing static attribute.
|
|
|
|
"""
|
|
if isinstance(self.argument, type):
|
|
mapper_ = mapper.class_mapper(self.argument,
|
|
configure=False)
|
|
elif isinstance(self.argument, mapper.Mapper):
|
|
mapper_ = self.argument
|
|
elif util.callable(self.argument):
|
|
|
|
# accept a callable to suit various deferred-
|
|
# configurational schemes
|
|
|
|
mapper_ = mapper.class_mapper(self.argument(),
|
|
configure=False)
|
|
else:
|
|
raise sa_exc.ArgumentError("relationship '%s' expects "
|
|
"a class or a mapper argument (received: %s)"
|
|
% (self.key, type(self.argument)))
|
|
assert isinstance(mapper_, mapper.Mapper), mapper_
|
|
return mapper_
|
|
|
|
@util.memoized_property
|
|
@util.deprecated("0.7", "Use .target")
|
|
def table(self):
|
|
"""Return the selectable linked to this
|
|
:class:`.RelationshipProperty` object's target
|
|
:class:`.Mapper`."""
|
|
return self.target
|
|
|
|
def do_init(self):
|
|
self._check_conflicts()
|
|
self._process_dependent_arguments()
|
|
self._setup_join_conditions()
|
|
self._check_cascade_settings(self._cascade)
|
|
self._post_init()
|
|
self._generate_backref()
|
|
super(RelationshipProperty, self).do_init()
|
|
|
|
def _process_dependent_arguments(self):
|
|
"""Convert incoming configuration arguments to their
|
|
proper form.
|
|
|
|
Callables are resolved, ORM annotations removed.
|
|
|
|
"""
|
|
# accept callables for other attributes which may require
|
|
# deferred initialization. This technique is used
|
|
# by declarative "string configs" and some recipes.
|
|
for attr in (
|
|
'order_by', 'primaryjoin', 'secondaryjoin',
|
|
'secondary', '_user_defined_foreign_keys', 'remote_side',
|
|
):
|
|
attr_value = getattr(self, attr)
|
|
if util.callable(attr_value):
|
|
setattr(self, attr, attr_value())
|
|
|
|
# remove "annotations" which are present if mapped class
|
|
# descriptors are used to create the join expression.
|
|
for attr in 'primaryjoin', 'secondaryjoin':
|
|
val = getattr(self, attr)
|
|
if val is not None:
|
|
setattr(self, attr, _orm_deannotate(
|
|
expression._only_column_elements(val, attr))
|
|
)
|
|
|
|
# ensure expressions in self.order_by, foreign_keys,
|
|
# remote_side are all columns, not strings.
|
|
if self.order_by is not False and self.order_by is not None:
|
|
self.order_by = [
|
|
expression._only_column_elements(x, "order_by")
|
|
for x in
|
|
util.to_list(self.order_by)]
|
|
|
|
self._user_defined_foreign_keys = \
|
|
util.column_set(
|
|
expression._only_column_elements(x, "foreign_keys")
|
|
for x in util.to_column_set(
|
|
self._user_defined_foreign_keys
|
|
))
|
|
|
|
self.remote_side = \
|
|
util.column_set(
|
|
expression._only_column_elements(x, "remote_side")
|
|
for x in
|
|
util.to_column_set(self.remote_side))
|
|
|
|
self.target = self.mapper.mapped_table
|
|
|
|
|
|
def _setup_join_conditions(self):
|
|
self._join_condition = jc = relationships.JoinCondition(
|
|
parent_selectable=self.parent.mapped_table,
|
|
child_selectable=self.mapper.mapped_table,
|
|
parent_local_selectable=self.parent.local_table,
|
|
child_local_selectable=self.mapper.local_table,
|
|
primaryjoin=self.primaryjoin,
|
|
secondary=self.secondary,
|
|
secondaryjoin=self.secondaryjoin,
|
|
parent_equivalents=self.parent._equivalent_columns,
|
|
child_equivalents=self.mapper._equivalent_columns,
|
|
consider_as_foreign_keys=self._user_defined_foreign_keys,
|
|
local_remote_pairs=self.local_remote_pairs,
|
|
remote_side=self.remote_side,
|
|
self_referential=self._is_self_referential,
|
|
prop=self,
|
|
support_sync=not self.viewonly,
|
|
can_be_synced_fn=self._columns_are_mapped
|
|
)
|
|
self.primaryjoin = jc.deannotated_primaryjoin
|
|
self.secondaryjoin = jc.deannotated_secondaryjoin
|
|
self.direction = jc.direction
|
|
self.local_remote_pairs = jc.local_remote_pairs
|
|
self.remote_side = jc.remote_columns
|
|
self.local_columns = jc.local_columns
|
|
self.synchronize_pairs = jc.synchronize_pairs
|
|
self._calculated_foreign_keys = jc.foreign_key_columns
|
|
self.secondary_synchronize_pairs = jc.secondary_synchronize_pairs
|
|
|
|
def _check_conflicts(self):
|
|
"""Test that this relationship is legal, warn about
|
|
inheritance conflicts."""
|
|
|
|
if not self.is_primary() \
|
|
and not mapper.class_mapper(
|
|
self.parent.class_,
|
|
configure=False).has_property(self.key):
|
|
raise sa_exc.ArgumentError("Attempting to assign a new "
|
|
"relationship '%s' to a non-primary mapper on "
|
|
"class '%s'. New relationships can only be added "
|
|
"to the primary mapper, i.e. the very first mapper "
|
|
"created for class '%s' " % (self.key,
|
|
self.parent.class_.__name__,
|
|
self.parent.class_.__name__))
|
|
|
|
# check for conflicting relationship() on superclass
|
|
if not self.parent.concrete:
|
|
for inheriting in self.parent.iterate_to_root():
|
|
if inheriting is not self.parent \
|
|
and inheriting.has_property(self.key):
|
|
util.warn("Warning: relationship '%s' on mapper "
|
|
"'%s' supersedes the same relationship "
|
|
"on inherited mapper '%s'; this can "
|
|
"cause dependency issues during flush"
|
|
% (self.key, self.parent, inheriting))
|
|
|
|
def _get_cascade(self):
|
|
"""Return the current cascade setting for this
|
|
:class:`.RelationshipProperty`.
|
|
"""
|
|
return self._cascade
|
|
|
|
def _set_cascade(self, cascade):
|
|
cascade = CascadeOptions(cascade)
|
|
if 'mapper' in self.__dict__:
|
|
self._check_cascade_settings(cascade)
|
|
self._cascade = cascade
|
|
|
|
if self._dependency_processor:
|
|
self._dependency_processor.cascade = cascade
|
|
|
|
cascade = property(_get_cascade, _set_cascade)
|
|
|
|
def _check_cascade_settings(self, cascade):
|
|
if cascade.delete_orphan and not self.single_parent \
|
|
and (self.direction is MANYTOMANY or self.direction
|
|
is MANYTOONE):
|
|
raise sa_exc.ArgumentError(
|
|
'On %s, delete-orphan cascade is not supported '
|
|
'on a many-to-many or many-to-one relationship '
|
|
'when single_parent is not set. Set '
|
|
'single_parent=True on the relationship().'
|
|
% self)
|
|
if self.direction is MANYTOONE and self.passive_deletes:
|
|
util.warn("On %s, 'passive_deletes' is normally configured "
|
|
"on one-to-many, one-to-one, many-to-many "
|
|
"relationships only."
|
|
% self)
|
|
|
|
if self.passive_deletes == 'all' and \
|
|
("delete" in cascade or
|
|
"delete-orphan" in cascade):
|
|
raise sa_exc.ArgumentError(
|
|
"On %s, can't set passive_deletes='all' in conjunction "
|
|
"with 'delete' or 'delete-orphan' cascade" % self)
|
|
|
|
if cascade.delete_orphan:
|
|
self.mapper.primary_mapper()._delete_orphans.append(
|
|
(self.key, self.parent.class_)
|
|
)
|
|
|
|
def _columns_are_mapped(self, *cols):
|
|
"""Return True if all columns in the given collection are
|
|
mapped by the tables referenced by this :class:`.Relationship`.
|
|
|
|
"""
|
|
for c in cols:
|
|
if self.secondary is not None \
|
|
and self.secondary.c.contains_column(c):
|
|
continue
|
|
if not self.parent.mapped_table.c.contains_column(c) and \
|
|
not self.target.c.contains_column(c):
|
|
return False
|
|
return True
|
|
|
|
def _generate_backref(self):
|
|
"""Interpret the 'backref' instruction to create a
|
|
:func:`.relationship` complementary to this one."""
|
|
|
|
if not self.is_primary():
|
|
return
|
|
if self.backref is not None and not self.back_populates:
|
|
if isinstance(self.backref, basestring):
|
|
backref_key, kwargs = self.backref, {}
|
|
else:
|
|
backref_key, kwargs = self.backref
|
|
mapper = self.mapper.primary_mapper()
|
|
|
|
check = set(mapper.iterate_to_root()).\
|
|
union(mapper.self_and_descendants)
|
|
for m in check:
|
|
if m.has_property(backref_key):
|
|
raise sa_exc.ArgumentError("Error creating backref "
|
|
"'%s' on relationship '%s': property of that "
|
|
"name exists on mapper '%s'" % (backref_key,
|
|
self, m))
|
|
|
|
# determine primaryjoin/secondaryjoin for the
|
|
# backref. Use the one we had, so that
|
|
# a custom join doesn't have to be specified in
|
|
# both directions.
|
|
if self.secondary is not None:
|
|
# for many to many, just switch primaryjoin/
|
|
# secondaryjoin. use the annotated
|
|
# pj/sj on the _join_condition.
|
|
pj = kwargs.pop('primaryjoin',
|
|
self._join_condition.secondaryjoin_minus_local)
|
|
sj = kwargs.pop('secondaryjoin',
|
|
self._join_condition.primaryjoin_minus_local)
|
|
else:
|
|
pj = kwargs.pop('primaryjoin',
|
|
self._join_condition.primaryjoin_reverse_remote)
|
|
sj = kwargs.pop('secondaryjoin', None)
|
|
if sj:
|
|
raise sa_exc.InvalidRequestError(
|
|
"Can't assign 'secondaryjoin' on a backref "
|
|
"against a non-secondary relationship."
|
|
)
|
|
|
|
foreign_keys = kwargs.pop('foreign_keys',
|
|
self._user_defined_foreign_keys)
|
|
parent = self.parent.primary_mapper()
|
|
kwargs.setdefault('viewonly', self.viewonly)
|
|
kwargs.setdefault('post_update', self.post_update)
|
|
kwargs.setdefault('passive_updates', self.passive_updates)
|
|
self.back_populates = backref_key
|
|
relationship = RelationshipProperty(
|
|
parent, self.secondary,
|
|
pj, sj,
|
|
foreign_keys=foreign_keys,
|
|
back_populates=self.key,
|
|
**kwargs)
|
|
mapper._configure_property(backref_key, relationship)
|
|
|
|
if self.back_populates:
|
|
self._add_reverse_property(self.back_populates)
|
|
|
|
def _post_init(self):
|
|
if self.uselist is None:
|
|
self.uselist = self.direction is not MANYTOONE
|
|
if not self.viewonly:
|
|
self._dependency_processor = \
|
|
dependency.DependencyProcessor.from_relationship(self)
|
|
|
|
@util.memoized_property
|
|
def _use_get(self):
|
|
"""memoize the 'use_get' attribute of this RelationshipLoader's
|
|
lazyloader."""
|
|
|
|
strategy = self._get_strategy(strategies.LazyLoader)
|
|
return strategy.use_get
|
|
|
|
@util.memoized_property
|
|
def _is_self_referential(self):
|
|
return self.mapper.common_parent(self.parent)
|
|
|
|
def _create_joins(self, source_polymorphic=False,
|
|
source_selectable=None, dest_polymorphic=False,
|
|
dest_selectable=None, of_type=None):
|
|
if source_selectable is None:
|
|
if source_polymorphic and self.parent.with_polymorphic:
|
|
source_selectable = self.parent._with_polymorphic_selectable
|
|
|
|
aliased = False
|
|
if dest_selectable is None:
|
|
if dest_polymorphic and self.mapper.with_polymorphic:
|
|
dest_selectable = self.mapper._with_polymorphic_selectable
|
|
aliased = True
|
|
else:
|
|
dest_selectable = self.mapper.mapped_table
|
|
|
|
if self._is_self_referential and source_selectable is None:
|
|
dest_selectable = dest_selectable.alias()
|
|
aliased = True
|
|
else:
|
|
aliased = True
|
|
|
|
dest_mapper = of_type or self.mapper
|
|
|
|
single_crit = dest_mapper._single_table_criterion
|
|
aliased = aliased or (source_selectable is not None)
|
|
|
|
primaryjoin, secondaryjoin, secondary, target_adapter, dest_selectable = \
|
|
self._join_condition.join_targets(
|
|
source_selectable, dest_selectable, aliased, single_crit
|
|
)
|
|
if source_selectable is None:
|
|
source_selectable = self.parent.local_table
|
|
if dest_selectable is None:
|
|
dest_selectable = self.mapper.local_table
|
|
return (primaryjoin, secondaryjoin, source_selectable,
|
|
dest_selectable, secondary, target_adapter)
|
|
|
|
|
|
PropertyLoader = RelationProperty = RelationshipProperty
|
|
log.class_logger(RelationshipProperty)
|