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908 lines
35 KiB
Python
908 lines
35 KiB
Python
# orm/relationships.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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"""Heuristics related to join conditions as used in
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:func:`.relationship`.
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Provides the :class:`.JoinCondition` object, which encapsulates
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SQL annotation and aliasing behavior focused on the `primaryjoin`
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and `secondaryjoin` aspects of :func:`.relationship`.
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"""
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from .. import sql, util, exc as sa_exc, schema
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from ..sql.util import (
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ClauseAdapter,
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join_condition, _shallow_annotate, visit_binary_product,
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_deep_deannotate, find_tables
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)
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from ..sql import operators, expression, visitors
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from .interfaces import MANYTOMANY, MANYTOONE, ONETOMANY
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def remote(expr):
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"""Annotate a portion of a primaryjoin expression
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with a 'remote' annotation.
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See the section :ref:`relationship_custom_foreign` for a
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description of use.
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.. versionadded:: 0.8
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.. seealso::
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:ref:`relationship_custom_foreign`
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:func:`.foreign`
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"""
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return _annotate_columns(expression._clause_element_as_expr(expr),
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{"remote": True})
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def foreign(expr):
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"""Annotate a portion of a primaryjoin expression
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with a 'foreign' annotation.
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See the section :ref:`relationship_custom_foreign` for a
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description of use.
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.. versionadded:: 0.8
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.. seealso::
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:ref:`relationship_custom_foreign`
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:func:`.remote`
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"""
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return _annotate_columns(expression._clause_element_as_expr(expr),
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{"foreign": True})
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def _annotate_columns(element, annotations):
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def clone(elem):
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if isinstance(elem, expression.ColumnClause):
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elem = elem._annotate(annotations.copy())
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elem._copy_internals(clone=clone)
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return elem
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if element is not None:
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element = clone(element)
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return element
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class JoinCondition(object):
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def __init__(self,
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parent_selectable,
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child_selectable,
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parent_local_selectable,
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child_local_selectable,
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primaryjoin=None,
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secondary=None,
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secondaryjoin=None,
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parent_equivalents=None,
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child_equivalents=None,
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consider_as_foreign_keys=None,
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local_remote_pairs=None,
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remote_side=None,
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self_referential=False,
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prop=None,
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support_sync=True,
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can_be_synced_fn=lambda *c: True
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):
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self.parent_selectable = parent_selectable
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self.parent_local_selectable = parent_local_selectable
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self.child_selectable = child_selectable
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self.child_local_selectable = child_local_selectable
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self.parent_equivalents = parent_equivalents
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self.child_equivalents = child_equivalents
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self.primaryjoin = primaryjoin
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self.secondaryjoin = secondaryjoin
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self.secondary = secondary
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self.consider_as_foreign_keys = consider_as_foreign_keys
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self._local_remote_pairs = local_remote_pairs
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self._remote_side = remote_side
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self.prop = prop
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self.self_referential = self_referential
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self.support_sync = support_sync
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self.can_be_synced_fn = can_be_synced_fn
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self._determine_joins()
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self._annotate_fks()
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self._annotate_remote()
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self._annotate_local()
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self._setup_pairs()
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self._check_foreign_cols(self.primaryjoin, True)
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if self.secondaryjoin is not None:
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self._check_foreign_cols(self.secondaryjoin, False)
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self._determine_direction()
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self._check_remote_side()
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self._log_joins()
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def _log_joins(self):
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if self.prop is None:
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return
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log = self.prop.logger
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log.info('%s setup primary join %s', self.prop,
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self.primaryjoin)
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log.info('%s setup secondary join %s', self.prop,
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self.secondaryjoin)
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log.info('%s synchronize pairs [%s]', self.prop,
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','.join('(%s => %s)' % (l, r) for (l, r) in
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self.synchronize_pairs))
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log.info('%s secondary synchronize pairs [%s]', self.prop,
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','.join('(%s => %s)' % (l, r) for (l, r) in
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self.secondary_synchronize_pairs or []))
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log.info('%s local/remote pairs [%s]', self.prop,
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','.join('(%s / %s)' % (l, r) for (l, r) in
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self.local_remote_pairs))
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log.info('%s remote columns [%s]', self.prop,
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','.join('%s' % col for col in self.remote_columns)
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)
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log.info('%s local columns [%s]', self.prop,
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','.join('%s' % col for col in self.local_columns)
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)
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log.info('%s relationship direction %s', self.prop,
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self.direction)
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def _determine_joins(self):
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"""Determine the 'primaryjoin' and 'secondaryjoin' attributes,
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if not passed to the constructor already.
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This is based on analysis of the foreign key relationships
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between the parent and target mapped selectables.
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"""
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if self.secondaryjoin is not None and self.secondary is None:
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raise sa_exc.ArgumentError(
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"Property %s specified with secondary "
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"join condition but "
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"no secondary argument" % self.prop)
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# find a join between the given mapper's mapped table and
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# the given table. will try the mapper's local table first
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# for more specificity, then if not found will try the more
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# general mapped table, which in the case of inheritance is
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# a join.
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try:
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consider_as_foreign_keys = self.consider_as_foreign_keys or None
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if self.secondary is not None:
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if self.secondaryjoin is None:
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self.secondaryjoin = \
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join_condition(
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self.child_selectable,
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self.secondary,
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a_subset=self.child_local_selectable,
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consider_as_foreign_keys=consider_as_foreign_keys
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)
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if self.primaryjoin is None:
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self.primaryjoin = \
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join_condition(
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self.parent_selectable,
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self.secondary,
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a_subset=self.parent_local_selectable,
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consider_as_foreign_keys=consider_as_foreign_keys
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)
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else:
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if self.primaryjoin is None:
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self.primaryjoin = \
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join_condition(
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self.parent_selectable,
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self.child_selectable,
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a_subset=self.parent_local_selectable,
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consider_as_foreign_keys=consider_as_foreign_keys
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)
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except sa_exc.NoForeignKeysError:
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if self.secondary is not None:
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raise sa_exc.NoForeignKeysError("Could not determine join "
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"condition between parent/child tables on "
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"relationship %s - there are no foreign keys "
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"linking these tables via secondary table '%s'. "
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"Ensure that referencing columns are associated "
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"with a ForeignKey or ForeignKeyConstraint, or "
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"specify 'primaryjoin' and 'secondaryjoin' "
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"expressions."
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% (self.prop, self.secondary))
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else:
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raise sa_exc.NoForeignKeysError("Could not determine join "
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"condition between parent/child tables on "
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"relationship %s - there are no foreign keys "
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"linking these tables. "
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"Ensure that referencing columns are associated "
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"with a ForeignKey or ForeignKeyConstraint, or "
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"specify a 'primaryjoin' expression."
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% self.prop)
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except sa_exc.AmbiguousForeignKeysError:
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if self.secondary is not None:
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raise sa_exc.AmbiguousForeignKeysError(
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"Could not determine join "
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"condition between parent/child tables on "
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"relationship %s - there are multiple foreign key "
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"paths linking the tables via secondary table '%s'. "
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"Specify the 'foreign_keys' "
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"argument, providing a list of those columns which "
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"should be counted as containing a foreign key "
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"reference from the secondary table to each of the "
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"parent and child tables."
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% (self.prop, self.secondary))
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else:
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raise sa_exc.AmbiguousForeignKeysError(
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"Could not determine join "
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"condition between parent/child tables on "
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"relationship %s - there are multiple foreign key "
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"paths linking the tables. Specify the "
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"'foreign_keys' argument, providing a list of those "
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"columns which should be counted as containing a "
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"foreign key reference to the parent table."
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% self.prop)
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@property
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def primaryjoin_minus_local(self):
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return _deep_deannotate(self.primaryjoin, values=("local", "remote"))
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@property
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def secondaryjoin_minus_local(self):
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return _deep_deannotate(self.secondaryjoin, values=("local", "remote"))
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@util.memoized_property
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def primaryjoin_reverse_remote(self):
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"""Return the primaryjoin condition suitable for the
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"reverse" direction.
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If the primaryjoin was delivered here with pre-existing
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"remote" annotations, the local/remote annotations
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are reversed. Otherwise, the local/remote annotations
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are removed.
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"""
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if self._has_remote_annotations:
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def replace(element):
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if "remote" in element._annotations:
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v = element._annotations.copy()
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del v['remote']
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v['local'] = True
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return element._with_annotations(v)
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elif "local" in element._annotations:
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v = element._annotations.copy()
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del v['local']
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v['remote'] = True
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return element._with_annotations(v)
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return visitors.replacement_traverse(
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self.primaryjoin, {}, replace)
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else:
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if self._has_foreign_annotations:
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# TODO: coverage
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return _deep_deannotate(self.primaryjoin,
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values=("local", "remote"))
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else:
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return _deep_deannotate(self.primaryjoin)
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def _has_annotation(self, clause, annotation):
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for col in visitors.iterate(clause, {}):
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if annotation in col._annotations:
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return True
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else:
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return False
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@util.memoized_property
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def _has_foreign_annotations(self):
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return self._has_annotation(self.primaryjoin, "foreign")
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@util.memoized_property
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def _has_remote_annotations(self):
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return self._has_annotation(self.primaryjoin, "remote")
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def _annotate_fks(self):
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"""Annotate the primaryjoin and secondaryjoin
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structures with 'foreign' annotations marking columns
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considered as foreign.
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"""
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if self._has_foreign_annotations:
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return
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if self.consider_as_foreign_keys:
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self._annotate_from_fk_list()
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else:
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self._annotate_present_fks()
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def _annotate_from_fk_list(self):
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def check_fk(col):
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if col in self.consider_as_foreign_keys:
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return col._annotate({"foreign": True})
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self.primaryjoin = visitors.replacement_traverse(
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self.primaryjoin,
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{},
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check_fk
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)
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if self.secondaryjoin is not None:
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self.secondaryjoin = visitors.replacement_traverse(
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self.secondaryjoin,
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{},
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check_fk
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)
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def _annotate_present_fks(self):
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if self.secondary is not None:
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secondarycols = util.column_set(self.secondary.c)
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else:
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secondarycols = set()
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def is_foreign(a, b):
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if isinstance(a, schema.Column) and \
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isinstance(b, schema.Column):
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if a.references(b):
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return a
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elif b.references(a):
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return b
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if secondarycols:
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if a in secondarycols and b not in secondarycols:
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return a
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elif b in secondarycols and a not in secondarycols:
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return b
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def visit_binary(binary):
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if not isinstance(binary.left, sql.ColumnElement) or \
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not isinstance(binary.right, sql.ColumnElement):
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return
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if "foreign" not in binary.left._annotations and \
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"foreign" not in binary.right._annotations:
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col = is_foreign(binary.left, binary.right)
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if col is not None:
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if col.compare(binary.left):
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binary.left = binary.left._annotate(
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{"foreign": True})
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elif col.compare(binary.right):
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binary.right = binary.right._annotate(
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{"foreign": True})
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self.primaryjoin = visitors.cloned_traverse(
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self.primaryjoin,
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{},
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{"binary": visit_binary}
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)
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if self.secondaryjoin is not None:
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self.secondaryjoin = visitors.cloned_traverse(
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self.secondaryjoin,
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{},
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{"binary": visit_binary}
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)
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def _refers_to_parent_table(self):
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"""Return True if the join condition contains column
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comparisons where both columns are in both tables.
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"""
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pt = self.parent_selectable
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mt = self.child_selectable
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result = [False]
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def visit_binary(binary):
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c, f = binary.left, binary.right
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if (
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isinstance(c, expression.ColumnClause) and \
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isinstance(f, expression.ColumnClause) and \
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pt.is_derived_from(c.table) and \
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pt.is_derived_from(f.table) and \
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mt.is_derived_from(c.table) and \
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mt.is_derived_from(f.table)
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):
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result[0] = True
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visitors.traverse(
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self.primaryjoin,
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{},
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{"binary": visit_binary}
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)
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return result[0]
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def _tables_overlap(self):
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"""Return True if parent/child tables have some overlap."""
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return bool(
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set(find_tables(self.parent_selectable)).intersection(
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find_tables(self.child_selectable)
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)
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)
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def _annotate_remote(self):
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"""Annotate the primaryjoin and secondaryjoin
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structures with 'remote' annotations marking columns
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considered as part of the 'remote' side.
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"""
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if self._has_remote_annotations:
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return
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if self.secondary is not None:
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self._annotate_remote_secondary()
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elif self._local_remote_pairs or self._remote_side:
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self._annotate_remote_from_args()
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elif self._refers_to_parent_table():
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self._annotate_selfref(lambda col: "foreign" in col._annotations)
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elif self._tables_overlap():
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self._annotate_remote_with_overlap()
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else:
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self._annotate_remote_distinct_selectables()
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def _annotate_remote_secondary(self):
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"""annotate 'remote' in primaryjoin, secondaryjoin
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when 'secondary' is present.
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"""
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def repl(element):
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if self.secondary.c.contains_column(element):
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return element._annotate({"remote": True})
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self.primaryjoin = visitors.replacement_traverse(
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self.primaryjoin, {}, repl)
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self.secondaryjoin = visitors.replacement_traverse(
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self.secondaryjoin, {}, repl)
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def _annotate_selfref(self, fn):
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"""annotate 'remote' in primaryjoin, secondaryjoin
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when the relationship is detected as self-referential.
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"""
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def visit_binary(binary):
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equated = binary.left.compare(binary.right)
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if isinstance(binary.left, expression.ColumnClause) and \
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isinstance(binary.right, expression.ColumnClause):
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# assume one to many - FKs are "remote"
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if fn(binary.left):
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binary.left = binary.left._annotate({"remote": True})
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if fn(binary.right) and not equated:
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binary.right = binary.right._annotate(
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{"remote": True})
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else:
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self._warn_non_column_elements()
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self.primaryjoin = visitors.cloned_traverse(
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self.primaryjoin, {},
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{"binary": visit_binary})
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def _annotate_remote_from_args(self):
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"""annotate 'remote' in primaryjoin, secondaryjoin
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when the 'remote_side' or '_local_remote_pairs'
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arguments are used.
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"""
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if self._local_remote_pairs:
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if self._remote_side:
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raise sa_exc.ArgumentError(
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"remote_side argument is redundant "
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"against more detailed _local_remote_side "
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"argument.")
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remote_side = [r for (l, r) in self._local_remote_pairs]
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else:
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remote_side = self._remote_side
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if self._refers_to_parent_table():
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self._annotate_selfref(lambda col: col in remote_side)
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else:
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def repl(element):
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if element in remote_side:
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return element._annotate({"remote": True})
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self.primaryjoin = visitors.replacement_traverse(
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self.primaryjoin, {}, repl)
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def _annotate_remote_with_overlap(self):
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"""annotate 'remote' in primaryjoin, secondaryjoin
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when the parent/child tables have some set of
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tables in common, though is not a fully self-referential
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relationship.
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"""
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def visit_binary(binary):
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binary.left, binary.right = proc_left_right(binary.left,
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binary.right)
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binary.right, binary.left = proc_left_right(binary.right,
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binary.left)
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def proc_left_right(left, right):
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if isinstance(left, expression.ColumnClause) and \
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isinstance(right, expression.ColumnClause):
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if self.child_selectable.c.contains_column(right) and \
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self.parent_selectable.c.contains_column(left):
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right = right._annotate({"remote": True})
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else:
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self._warn_non_column_elements()
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return left, right
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self.primaryjoin = visitors.cloned_traverse(
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self.primaryjoin, {},
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{"binary": visit_binary})
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def _annotate_remote_distinct_selectables(self):
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"""annotate 'remote' in primaryjoin, secondaryjoin
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when the parent/child tables are entirely
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separate.
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"""
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def repl(element):
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if self.child_selectable.c.contains_column(element) and \
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(
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not self.parent_local_selectable.c.\
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contains_column(element)
|
|
or self.child_local_selectable.c.\
|
|
contains_column(element)):
|
|
return element._annotate({"remote": True})
|
|
self.primaryjoin = visitors.replacement_traverse(
|
|
self.primaryjoin, {}, repl)
|
|
|
|
def _warn_non_column_elements(self):
|
|
util.warn(
|
|
"Non-simple column elements in primary "
|
|
"join condition for property %s - consider using "
|
|
"remote() annotations to mark the remote side."
|
|
% self.prop
|
|
)
|
|
|
|
def _annotate_local(self):
|
|
"""Annotate the primaryjoin and secondaryjoin
|
|
structures with 'local' annotations.
|
|
|
|
This annotates all column elements found
|
|
simultaneously in the parent table
|
|
and the join condition that don't have a
|
|
'remote' annotation set up from
|
|
_annotate_remote() or user-defined.
|
|
|
|
"""
|
|
if self._has_annotation(self.primaryjoin, "local"):
|
|
return
|
|
|
|
if self._local_remote_pairs:
|
|
local_side = util.column_set([l for (l, r)
|
|
in self._local_remote_pairs])
|
|
else:
|
|
local_side = util.column_set(self.parent_selectable.c)
|
|
|
|
def locals_(elem):
|
|
if "remote" not in elem._annotations and \
|
|
elem in local_side:
|
|
return elem._annotate({"local": True})
|
|
self.primaryjoin = visitors.replacement_traverse(
|
|
self.primaryjoin, {}, locals_
|
|
)
|
|
|
|
def _check_remote_side(self):
|
|
if not self.local_remote_pairs:
|
|
raise sa_exc.ArgumentError('Relationship %s could '
|
|
'not determine any unambiguous local/remote column '
|
|
'pairs based on join condition and remote_side '
|
|
'arguments. '
|
|
'Consider using the remote() annotation to '
|
|
'accurately mark those elements of the join '
|
|
'condition that are on the remote side of '
|
|
'the relationship.'
|
|
% (self.prop, ))
|
|
|
|
def _check_foreign_cols(self, join_condition, primary):
|
|
"""Check the foreign key columns collected and emit error
|
|
messages."""
|
|
|
|
can_sync = False
|
|
|
|
foreign_cols = self._gather_columns_with_annotation(
|
|
join_condition, "foreign")
|
|
|
|
has_foreign = bool(foreign_cols)
|
|
|
|
if primary:
|
|
can_sync = bool(self.synchronize_pairs)
|
|
else:
|
|
can_sync = bool(self.secondary_synchronize_pairs)
|
|
|
|
if self.support_sync and can_sync or \
|
|
(not self.support_sync and has_foreign):
|
|
return
|
|
|
|
# from here below is just determining the best error message
|
|
# to report. Check for a join condition using any operator
|
|
# (not just ==), perhaps they need to turn on "viewonly=True".
|
|
if self.support_sync and has_foreign and not can_sync:
|
|
err = "Could not locate any simple equality expressions "\
|
|
"involving locally mapped foreign key columns for "\
|
|
"%s join condition "\
|
|
"'%s' on relationship %s." % (
|
|
primary and 'primary' or 'secondary',
|
|
join_condition,
|
|
self.prop
|
|
)
|
|
err += \
|
|
" Ensure that referencing columns are associated "\
|
|
"with a ForeignKey or ForeignKeyConstraint, or are "\
|
|
"annotated in the join condition with the foreign() "\
|
|
"annotation. To allow comparison operators other than "\
|
|
"'==', the relationship can be marked as viewonly=True."
|
|
|
|
raise sa_exc.ArgumentError(err)
|
|
else:
|
|
err = "Could not locate any relevant foreign key columns "\
|
|
"for %s join condition '%s' on relationship %s." % (
|
|
primary and 'primary' or 'secondary',
|
|
join_condition,
|
|
self.prop
|
|
)
|
|
err += \
|
|
' Ensure that referencing columns are associated '\
|
|
'with a ForeignKey or ForeignKeyConstraint, or are '\
|
|
'annotated in the join condition with the foreign() '\
|
|
'annotation.'
|
|
raise sa_exc.ArgumentError(err)
|
|
|
|
def _determine_direction(self):
|
|
"""Determine if this relationship is one to many, many to one,
|
|
many to many.
|
|
|
|
"""
|
|
if self.secondaryjoin is not None:
|
|
self.direction = MANYTOMANY
|
|
else:
|
|
parentcols = util.column_set(self.parent_selectable.c)
|
|
targetcols = util.column_set(self.child_selectable.c)
|
|
|
|
# fk collection which suggests ONETOMANY.
|
|
onetomany_fk = targetcols.intersection(
|
|
self.foreign_key_columns)
|
|
|
|
# fk collection which suggests MANYTOONE.
|
|
|
|
manytoone_fk = parentcols.intersection(
|
|
self.foreign_key_columns)
|
|
|
|
if onetomany_fk and manytoone_fk:
|
|
# fks on both sides. test for overlap of local/remote
|
|
# with foreign key
|
|
self_equated = self.remote_columns.intersection(
|
|
self.local_columns
|
|
)
|
|
onetomany_local = self.remote_columns.\
|
|
intersection(self.foreign_key_columns).\
|
|
difference(self_equated)
|
|
manytoone_local = self.local_columns.\
|
|
intersection(self.foreign_key_columns).\
|
|
difference(self_equated)
|
|
if onetomany_local and not manytoone_local:
|
|
self.direction = ONETOMANY
|
|
elif manytoone_local and not onetomany_local:
|
|
self.direction = MANYTOONE
|
|
else:
|
|
raise sa_exc.ArgumentError(
|
|
"Can't determine relationship"
|
|
" direction for relationship '%s' - foreign "
|
|
"key columns within the join condition are present "
|
|
"in both the parent and the child's mapped tables. "
|
|
"Ensure that only those columns referring "
|
|
"to a parent column are marked as foreign, "
|
|
"either via the foreign() annotation or "
|
|
"via the foreign_keys argument." % self.prop)
|
|
elif onetomany_fk:
|
|
self.direction = ONETOMANY
|
|
elif manytoone_fk:
|
|
self.direction = MANYTOONE
|
|
else:
|
|
raise sa_exc.ArgumentError("Can't determine relationship "
|
|
"direction for relationship '%s' - foreign "
|
|
"key columns are present in neither the parent "
|
|
"nor the child's mapped tables" % self.prop)
|
|
|
|
def _deannotate_pairs(self, collection):
|
|
"""provide deannotation for the various lists of
|
|
pairs, so that using them in hashes doesn't incur
|
|
high-overhead __eq__() comparisons against
|
|
original columns mapped.
|
|
|
|
"""
|
|
return [(x._deannotate(), y._deannotate())
|
|
for x, y in collection]
|
|
|
|
def _setup_pairs(self):
|
|
sync_pairs = []
|
|
lrp = util.OrderedSet([])
|
|
secondary_sync_pairs = []
|
|
|
|
def go(joincond, collection):
|
|
def visit_binary(binary, left, right):
|
|
if "remote" in right._annotations and \
|
|
"remote" not in left._annotations and \
|
|
self.can_be_synced_fn(left):
|
|
lrp.add((left, right))
|
|
elif "remote" in left._annotations and \
|
|
"remote" not in right._annotations and \
|
|
self.can_be_synced_fn(right):
|
|
lrp.add((right, left))
|
|
if binary.operator is operators.eq and \
|
|
self.can_be_synced_fn(left, right):
|
|
if "foreign" in right._annotations:
|
|
collection.append((left, right))
|
|
elif "foreign" in left._annotations:
|
|
collection.append((right, left))
|
|
visit_binary_product(visit_binary, joincond)
|
|
|
|
for joincond, collection in [
|
|
(self.primaryjoin, sync_pairs),
|
|
(self.secondaryjoin, secondary_sync_pairs)
|
|
]:
|
|
if joincond is None:
|
|
continue
|
|
go(joincond, collection)
|
|
|
|
self.local_remote_pairs = self._deannotate_pairs(lrp)
|
|
self.synchronize_pairs = self._deannotate_pairs(sync_pairs)
|
|
self.secondary_synchronize_pairs = \
|
|
self._deannotate_pairs(secondary_sync_pairs)
|
|
|
|
@util.memoized_property
|
|
def remote_columns(self):
|
|
return self._gather_join_annotations("remote")
|
|
|
|
@util.memoized_property
|
|
def local_columns(self):
|
|
return self._gather_join_annotations("local")
|
|
|
|
@util.memoized_property
|
|
def foreign_key_columns(self):
|
|
return self._gather_join_annotations("foreign")
|
|
|
|
@util.memoized_property
|
|
def deannotated_primaryjoin(self):
|
|
return _deep_deannotate(self.primaryjoin)
|
|
|
|
@util.memoized_property
|
|
def deannotated_secondaryjoin(self):
|
|
if self.secondaryjoin is not None:
|
|
return _deep_deannotate(self.secondaryjoin)
|
|
else:
|
|
return None
|
|
|
|
def _gather_join_annotations(self, annotation):
|
|
s = set(
|
|
self._gather_columns_with_annotation(
|
|
self.primaryjoin, annotation)
|
|
)
|
|
if self.secondaryjoin is not None:
|
|
s.update(
|
|
self._gather_columns_with_annotation(
|
|
self.secondaryjoin, annotation)
|
|
)
|
|
return set([x._deannotate() for x in s])
|
|
|
|
def _gather_columns_with_annotation(self, clause, *annotation):
|
|
annotation = set(annotation)
|
|
return set([
|
|
col for col in visitors.iterate(clause, {})
|
|
if annotation.issubset(col._annotations)
|
|
])
|
|
|
|
def join_targets(self, source_selectable,
|
|
dest_selectable,
|
|
aliased,
|
|
single_crit=None):
|
|
"""Given a source and destination selectable, create a
|
|
join between them.
|
|
|
|
This takes into account aliasing the join clause
|
|
to reference the appropriate corresponding columns
|
|
in the target objects, as well as the extra child
|
|
criterion, equivalent column sets, etc.
|
|
|
|
"""
|
|
|
|
# place a barrier on the destination such that
|
|
# replacement traversals won't ever dig into it.
|
|
# its internal structure remains fixed
|
|
# regardless of context.
|
|
dest_selectable = _shallow_annotate(
|
|
dest_selectable,
|
|
{'no_replacement_traverse': True})
|
|
|
|
primaryjoin, secondaryjoin, secondary = self.primaryjoin, \
|
|
self.secondaryjoin, self.secondary
|
|
|
|
# adjust the join condition for single table inheritance,
|
|
# in the case that the join is to a subclass
|
|
# this is analogous to the
|
|
# "_adjust_for_single_table_inheritance()" method in Query.
|
|
|
|
if single_crit is not None:
|
|
if secondaryjoin is not None:
|
|
secondaryjoin = secondaryjoin & single_crit
|
|
else:
|
|
primaryjoin = primaryjoin & single_crit
|
|
|
|
if aliased:
|
|
if secondary is not None:
|
|
secondary = secondary.alias()
|
|
primary_aliasizer = ClauseAdapter(secondary)
|
|
secondary_aliasizer = \
|
|
ClauseAdapter(dest_selectable,
|
|
equivalents=self.child_equivalents).\
|
|
chain(primary_aliasizer)
|
|
if source_selectable is not None:
|
|
primary_aliasizer = \
|
|
ClauseAdapter(secondary).\
|
|
chain(ClauseAdapter(source_selectable,
|
|
equivalents=self.parent_equivalents))
|
|
secondaryjoin = \
|
|
secondary_aliasizer.traverse(secondaryjoin)
|
|
else:
|
|
primary_aliasizer = ClauseAdapter(dest_selectable,
|
|
exclude_fn=_ColInAnnotations("local"),
|
|
equivalents=self.child_equivalents)
|
|
if source_selectable is not None:
|
|
primary_aliasizer.chain(
|
|
ClauseAdapter(source_selectable,
|
|
exclude_fn=_ColInAnnotations("remote"),
|
|
equivalents=self.parent_equivalents))
|
|
secondary_aliasizer = None
|
|
|
|
primaryjoin = primary_aliasizer.traverse(primaryjoin)
|
|
target_adapter = secondary_aliasizer or primary_aliasizer
|
|
target_adapter.exclude_fn = None
|
|
else:
|
|
target_adapter = None
|
|
return primaryjoin, secondaryjoin, secondary, \
|
|
target_adapter, dest_selectable
|
|
|
|
def create_lazy_clause(self, reverse_direction=False):
|
|
binds = util.column_dict()
|
|
lookup = util.column_dict()
|
|
equated_columns = util.column_dict()
|
|
|
|
if reverse_direction and self.secondaryjoin is None:
|
|
for l, r in self.local_remote_pairs:
|
|
_list = lookup.setdefault(r, [])
|
|
_list.append((r, l))
|
|
equated_columns[l] = r
|
|
else:
|
|
for l, r in self.local_remote_pairs:
|
|
_list = lookup.setdefault(l, [])
|
|
_list.append((l, r))
|
|
equated_columns[r] = l
|
|
|
|
def col_to_bind(col):
|
|
if col in lookup:
|
|
for tobind, equated in lookup[col]:
|
|
if equated in binds:
|
|
return None
|
|
if col not in binds:
|
|
binds[col] = sql.bindparam(
|
|
None, None, type_=col.type, unique=True)
|
|
return binds[col]
|
|
return None
|
|
|
|
lazywhere = self.deannotated_primaryjoin
|
|
|
|
if self.deannotated_secondaryjoin is None or not reverse_direction:
|
|
lazywhere = visitors.replacement_traverse(
|
|
lazywhere, {}, col_to_bind)
|
|
|
|
if self.deannotated_secondaryjoin is not None:
|
|
secondaryjoin = self.deannotated_secondaryjoin
|
|
if reverse_direction:
|
|
secondaryjoin = visitors.replacement_traverse(
|
|
secondaryjoin, {}, col_to_bind)
|
|
lazywhere = sql.and_(lazywhere, secondaryjoin)
|
|
|
|
bind_to_col = dict((binds[col].key, col) for col in binds)
|
|
|
|
return lazywhere, bind_to_col, equated_columns
|
|
|
|
class _ColInAnnotations(object):
|
|
"""Seralizable equivalent to:
|
|
|
|
lambda c: "name" in c._annotations
|
|
"""
|
|
def __init__(self, name):
|
|
self.name = name
|
|
|
|
def __call__(self, c):
|
|
return self.name in c._annotations |