diff options
Diffstat (limited to 'lib/sqlalchemy/orm/properties.py')
| -rw-r--r-- | lib/sqlalchemy/orm/properties.py | 190 |
1 files changed, 110 insertions, 80 deletions
diff --git a/lib/sqlalchemy/orm/properties.py b/lib/sqlalchemy/orm/properties.py index cbfba91f3..5788c30f9 100644 --- a/lib/sqlalchemy/orm/properties.py +++ b/lib/sqlalchemy/orm/properties.py @@ -446,7 +446,7 @@ class RelationshipProperty(StrategizedProperty): self.viewonly = viewonly self.lazy = lazy self.single_parent = single_parent - self._foreign_keys = foreign_keys + self._user_defined_foreign_keys = foreign_keys self.collection_class = collection_class self.passive_deletes = passive_deletes self.passive_updates = passive_updates @@ -695,7 +695,7 @@ class RelationshipProperty(StrategizedProperty): if isinstance(other, (NoneType, expression._Null)): if self.property.direction == MANYTOONE: return sql.or_(*[x != None for x in - self.property._foreign_keys]) + self.property._calculated_foreign_keys]) else: return self._criterion_exists() elif self.property.uselist: @@ -912,7 +912,7 @@ class RelationshipProperty(StrategizedProperty): 'primaryjoin', 'secondaryjoin', 'secondary', - '_foreign_keys', + '_user_defined_foreign_keys', 'remote_side', ): if util.callable(getattr(self, attr)): @@ -931,9 +931,9 @@ class RelationshipProperty(StrategizedProperty): if self.order_by is not False and self.order_by is not None: self.order_by = [expression._literal_as_column(x) for x in util.to_list(self.order_by)] - self._foreign_keys = \ + self._user_defined_foreign_keys = \ util.column_set(expression._literal_as_column(x) for x in - util.to_column_set(self._foreign_keys)) + util.to_column_set(self._user_defined_foreign_keys)) self.remote_side = \ util.column_set(expression._literal_as_column(x) for x in util.to_column_set(self.remote_side)) @@ -999,8 +999,8 @@ class RelationshipProperty(StrategizedProperty): raise sa_exc.ArgumentError("Could not determine join " "condition between parent/child tables on " "relationship %s. Specify a 'primaryjoin' " - "expression. If this is a many-to-many " - "relationship, 'secondaryjoin' is needed as well." + "expression. If 'secondary' is present, " + "'secondaryjoin' is needed as well." % self) def _col_is_part_of_mappings(self, column): @@ -1012,91 +1012,121 @@ class RelationshipProperty(StrategizedProperty): self.target.c.contains_column(column) or \ self.secondary.c.contains_column(column) is not None + def _sync_pairs_from_join(self, join_condition, primary): + """Given a join condition, figure out what columns are foreign + and are part of a binary "equated" condition to their referecned + columns, and convert into a list of tuples of (primary col->foreign col). + + Make several attempts to determine if cols are compared using + "=" or other comparators (in which case suggest viewonly), + columns are present but not part of the expected mappings, columns + don't have any :class:`ForeignKey` information on them, or + the ``foreign_keys`` attribute is being used incorrectly. + + """ + eq_pairs = criterion_as_pairs(join_condition, + consider_as_foreign_keys=self._user_defined_foreign_keys, + any_operator=self.viewonly) + + eq_pairs = [(l, r) for (l, r) in eq_pairs + if self._col_is_part_of_mappings(l) + and self._col_is_part_of_mappings(r) + or self.viewonly and r in self._user_defined_foreign_keys] + + if not eq_pairs and \ + self.secondary is not None and \ + not self._user_defined_foreign_keys: + fks = set(self.secondary.c) + eq_pairs = criterion_as_pairs(join_condition, + consider_as_foreign_keys=fks, + any_operator=self.viewonly) + + eq_pairs = [(l, r) for (l, r) in eq_pairs + if self._col_is_part_of_mappings(l) + and self._col_is_part_of_mappings(r) + or self.viewonly and r in fks] + if eq_pairs: + util.warn("No ForeignKey objects were present " + "in secondary table '%s'. Assumed referenced " + "foreign key columns %s for join condition '%s' " + "on relationship %s" % ( + self.secondary.description, + ", ".join(sorted(["'%s'" % col for col in fks])), + join_condition, + self + )) + + if not eq_pairs: + if not self.viewonly and criterion_as_pairs(join_condition, + consider_as_foreign_keys=self._user_defined_foreign_keys, + any_operator=True): + raise sa_exc.ArgumentError("Could not locate any " + "equated, locally mapped column pairs for %s " + "condition '%s' on relationship %s. For more " + "relaxed rules on join conditions, the " + "relationship may be marked as viewonly=True." + % ( + primary and 'primaryjoin' or 'secondaryjoin', + join_condition, + self + )) + else: + if self._user_defined_foreign_keys: + raise sa_exc.ArgumentError("Could not determine " + "relationship direction for %s condition " + "'%s', on relationship %s, using manual " + "'foreign_keys' setting. Do the columns " + "in 'foreign_keys' represent all, and " + "only, the 'foreign' columns in this join " + "condition? Does the %s Table already " + "have adequate ForeignKey and/or " + "ForeignKeyConstraint objects established " + "(in which case 'foreign_keys' is usually " + "unnecessary)?" + % ( + primary and 'primaryjoin' or 'secondaryjoin', + join_condition, + self, + primary and 'mapped' or 'secondary' + )) + else: + raise sa_exc.ArgumentError("Could not determine " + "relationship direction for %s condition " + "'%s', on relationship %s. Ensure that the " + "referencing Column objects have a " + "ForeignKey present, or are otherwise part " + "of a ForeignKeyConstraint on their parent " + "Table." + % ( + primary and 'primaryjoin' or 'secondaryjoin', + join_condition, + self + )) + return eq_pairs + def _determine_synchronize_pairs(self): if self.local_remote_pairs: - if not self._foreign_keys: + if not self._user_defined_foreign_keys: raise sa_exc.ArgumentError('foreign_keys argument is ' 'required with _local_remote_pairs argument') self.synchronize_pairs = [] for l, r in self.local_remote_pairs: - if r in self._foreign_keys: + if r in self._user_defined_foreign_keys: self.synchronize_pairs.append((l, r)) - elif l in self._foreign_keys: + elif l in self._user_defined_foreign_keys: self.synchronize_pairs.append((r, l)) else: - eq_pairs = criterion_as_pairs(self.primaryjoin, - consider_as_foreign_keys=self._foreign_keys, - any_operator=self.viewonly) - eq_pairs = [(l, r) for (l, r) in eq_pairs - if self._col_is_part_of_mappings(l) - and self._col_is_part_of_mappings(r) - or self.viewonly and r in self._foreign_keys] - if not eq_pairs: - if not self.viewonly \ - and criterion_as_pairs(self.primaryjoin, - consider_as_foreign_keys=self._foreign_keys, - any_operator=True): - raise sa_exc.ArgumentError("Could not locate any " - "equated, locally mapped column pairs for " - "primaryjoin condition '%s' on " - "relationship %s. For more relaxed rules " - "on join conditions, the relationship may " - "be marked as viewonly=True." - % (self.primaryjoin, self)) - else: - if self._foreign_keys: - raise sa_exc.ArgumentError("Could not determine" - " relationship direction for " - "primaryjoin condition '%s', on " - "relationship %s. Do the columns in " - "'foreign_keys' represent only the " - "'foreign' columns in this join " - "condition ?" % (self.primaryjoin, - self)) - else: - raise sa_exc.ArgumentError("Could not determine" - " relationship direction for " - "primaryjoin condition '%s', on " - "relationship %s. Specify the " - "'foreign_keys' argument to indicate " - "which columns on the relationship are " - "foreign." % (self.primaryjoin, self)) + eq_pairs = self._sync_pairs_from_join(self.primaryjoin, True) self.synchronize_pairs = eq_pairs if self.secondaryjoin is not None: - sq_pairs = criterion_as_pairs(self.secondaryjoin, - consider_as_foreign_keys=self._foreign_keys, - any_operator=self.viewonly) - sq_pairs = [(l, r) for (l, r) in sq_pairs - if self._col_is_part_of_mappings(l) - and self._col_is_part_of_mappings(r) or r - in self._foreign_keys] - if not sq_pairs: - if not self.viewonly \ - and criterion_as_pairs(self.secondaryjoin, - consider_as_foreign_keys=self._foreign_keys, - any_operator=True): - raise sa_exc.ArgumentError("Could not locate any " - "equated, locally mapped column pairs for " - "secondaryjoin condition '%s' on " - "relationship %s. For more relaxed rules " - "on join conditions, the relationship may " - "be marked as viewonly=True." - % (self.secondaryjoin, self)) - else: - raise sa_exc.ArgumentError("Could not determine " - "relationship direction for secondaryjoin " - "condition '%s', on relationship %s. " - "Specify the foreign_keys argument to " - "indicate which columns on the " - "relationship are foreign." - % (self.secondaryjoin, self)) + sq_pairs = self._sync_pairs_from_join(self.secondaryjoin, False) self.secondary_synchronize_pairs = sq_pairs else: self.secondary_synchronize_pairs = None - self._foreign_keys = util.column_set(r for (l, r) in + self._calculated_foreign_keys = util.column_set(r for (l, r) in self.synchronize_pairs) if self.secondary_synchronize_pairs: - self._foreign_keys.update(r for (l, r) in + self._calculated_foreign_keys.update(r for (l, r) in self.secondary_synchronize_pairs) def _determine_direction(self): @@ -1114,7 +1144,7 @@ class RelationshipProperty(StrategizedProperty): remote = self.remote_side else: remote = None - if not remote or self._foreign_keys.difference(l for (l, + if not remote or self._calculated_foreign_keys.difference(l for (l, r) in self.synchronize_pairs).intersection(remote): self.direction = ONETOMANY else: @@ -1192,12 +1222,12 @@ class RelationshipProperty(StrategizedProperty): eq_pairs += self.secondary_synchronize_pairs else: eq_pairs = criterion_as_pairs(self.primaryjoin, - consider_as_foreign_keys=self._foreign_keys, + consider_as_foreign_keys=self._calculated_foreign_keys, any_operator=True) if self.secondaryjoin is not None: eq_pairs += \ criterion_as_pairs(self.secondaryjoin, - consider_as_foreign_keys=self._foreign_keys, + consider_as_foreign_keys=self._calculated_foreign_keys, any_operator=True) eq_pairs = [(l, r) for (l, r) in eq_pairs if self._col_is_part_of_mappings(l) @@ -1266,7 +1296,7 @@ class RelationshipProperty(StrategizedProperty): "a non-secondary relationship." ) foreign_keys = kwargs.pop('foreign_keys', - self._foreign_keys) + self._user_defined_foreign_keys) parent = self.parent.primary_mapper() kwargs.setdefault('viewonly', self.viewonly) kwargs.setdefault('post_update', self.post_update) |