diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 39 | ||||
| -rw-r--r-- | lib/sqlalchemy/sql/util.py | 23 | ||||
| -rw-r--r-- | lib/sqlalchemy/sql/visitors.py | 15 |
3 files changed, 52 insertions, 25 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index 6276f33bd..e066632af 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -844,6 +844,14 @@ class ClauseElement(object): """ c = self.__class__.__new__(self.__class__) c.__dict__ = self.__dict__.copy() + + # this is a marker that helps to "equate" clauses to each other + # when a Select returns its list of FROM clauses. the cloning + # process leaves around a lot of remnants of the previous clause + # typically in the form of column expressions still attached to the + # old table. + c._is_clone_of = self + return c def _get_from_objects(self, **modifiers): @@ -2212,7 +2220,7 @@ class Join(FromClause): self.__primary_key = ColumnSet([c for c in self._flatten_exportable_columns() if c.primary_key and c not in omit]) def description(self): - return "Join object on %s and %s" % (self.left.description, self.right.description) + return "Join object on %s(%d) and %s(%d)" % (self.left.description, id(self.left), self.right.description, id(self.right)) description = property(description) primary_key = property(lambda s:s.__primary_key) @@ -2394,15 +2402,6 @@ class Alias(FromClause): #return self.selectable._exportable_columns() return self.selectable.columns - def _clone(self): - # TODO: need test coverage to assert ClauseAdapter behavior - # here; must identify non-ORM failure cases when a. _clone() returns 'self' in all - # cases and b. when _clone() does an actual _clone() in all cases. - if isinstance(self.selectable, TableClause): - return self - else: - return super(Alias, self)._clone() - def _copy_internals(self, clone=_clone): self._clone_from_clause() self.selectable = _clone(self.selectable) @@ -2996,6 +2995,9 @@ class Select(_SelectBaseMixin, FromClause): for col in self._raw_columns: for f in col._hide_froms(): hide_froms.add(f) + while hasattr(f, '_is_clone_of'): + hide_froms.add(f._is_clone_of) + f = f._is_clone_of for f in col._get_from_objects(): froms.add(f) @@ -3007,17 +3009,26 @@ class Select(_SelectBaseMixin, FromClause): froms.add(elem) for f in elem._get_from_objects(): froms.add(f) - + for elem in froms: for f in elem._hide_froms(): hide_froms.add(f) - + while hasattr(f, '_is_clone_of'): + hide_froms.add(f._is_clone_of) + f = f._is_clone_of + froms = froms.difference(hide_froms) - + if len(froms) > 1: corr = self.__correlate if self._should_correlate and existing_froms is not None: corr = existing_froms.union(corr) + + for f in list(corr): + while hasattr(f, '_is_clone_of'): + corr.add(f._is_clone_of) + f = f._is_clone_of + f = froms.difference(corr) if len(f) == 0: raise exceptions.InvalidRequestError("Select statement '%s' is overcorrelated; returned no 'from' clauses" % str(self.__dont_correlate())) @@ -3070,8 +3081,8 @@ class Select(_SelectBaseMixin, FromClause): def _copy_internals(self, clone=_clone): self._clone_from_clause() - self._raw_columns = [clone(c) for c in self._raw_columns] self._recorrelate_froms([(f, clone(f)) for f in self._froms]) + self._raw_columns = [clone(c) for c in self._raw_columns] for attr in ('_whereclause', '_having', '_order_by_clause', '_group_by_clause'): if getattr(self, attr) is not None: setattr(self, attr, clone(getattr(self, attr))) diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py index ecf4f3c16..81d28ac7e 100644 --- a/lib/sqlalchemy/sql/util.py +++ b/lib/sqlalchemy/sql/util.py @@ -148,7 +148,7 @@ class AbstractClauseProcessor(object): list_[i] = self.traverse(list_[i], stop_on=stop_on) return list_ - def _convert_element(self, elem, stop_on): + def _convert_element(self, elem, stop_on, cloned): v = self while v is not None: newelem = v.convert_element(elem) @@ -156,25 +156,32 @@ class AbstractClauseProcessor(object): stop_on.add(newelem) return newelem v = getattr(v, '_next_acp', None) - return elem._clone() - def traverse(self, elem, clone=True, stop_on=None, _clone_toplevel=True): + if elem not in cloned: + # the full traversal will only make a clone of a particular element + # once. + cloned[elem] = elem._clone() + return cloned[elem] + + def traverse(self, elem, clone=True, stop_on=None): if not clone: raise exceptions.ArgumentError("AbstractClauseProcessor 'clone' argument must be True") - + if stop_on is None: stop_on = util.Set() - + return self._traverse(elem, stop_on, {}, _clone_toplevel=True) + + def _traverse(self, elem, stop_on, cloned, _clone_toplevel=False): if elem in stop_on: return elem if _clone_toplevel: - elem = self._convert_element(elem, stop_on) + elem = self._convert_element(elem, stop_on, cloned) if elem in stop_on: return elem def clone(element): - return self._convert_element(element, stop_on) + return self._convert_element(element, stop_on, cloned) elem._copy_internals(clone=clone) v = getattr(self, '_next', None) @@ -186,7 +193,7 @@ class AbstractClauseProcessor(object): for e in elem.get_children(**self.__traverse_options__): if e not in stop_on: - self.traverse(e, stop_on=stop_on, _clone_toplevel=False) + self._traverse(e, stop_on, cloned) return elem class ClauseAdapter(AbstractClauseProcessor): diff --git a/lib/sqlalchemy/sql/visitors.py b/lib/sqlalchemy/sql/visitors.py index 9bc5d2479..1a0629a17 100644 --- a/lib/sqlalchemy/sql/visitors.py +++ b/lib/sqlalchemy/sql/visitors.py @@ -47,10 +47,19 @@ class ClauseVisitor(object): traversal.insert(0, t) for c in t.get_children(**self.__traverse_options__): stack.append(c) - + def traverse(self, obj, stop_on=None, clone=False): + if clone: - obj = obj._clone() + cloned = {} + def do_clone(obj): + # the full traversal will only make a clone of a particular element + # once. + if obj not in cloned: + cloned[obj] = obj._clone() + return cloned[obj] + + obj = do_clone(obj) stack = [obj] traversal = [] @@ -59,7 +68,7 @@ class ClauseVisitor(object): if stop_on is None or t not in stop_on: traversal.insert(0, t) if clone: - t._copy_internals() + t._copy_internals(clone=do_clone) for c in t.get_children(**self.__traverse_options__): stack.append(c) for target in traversal: |