diff options
Diffstat (limited to 'lib/sqlalchemy/sql/expression.py')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 85 |
1 files changed, 48 insertions, 37 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index 1b9ae6e8f..0ece67e20 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -974,7 +974,7 @@ def _no_literals(element): def _corresponding_column_or_error(fromclause, column, require_embedded=False): c = fromclause.corresponding_column(column, require_embedded=require_embedded) - if not c: + if c is None: raise exc.InvalidRequestError( "Given column '%s', attached to table '%s', " "failed to locate a corresponding column from table '%s'" @@ -1044,7 +1044,18 @@ class ClauseElement(Visitable): d = self.__dict__.copy() d.pop('_is_clone_of', None) return d - + + if util.jython: + def __hash__(self): + """Return a distinct hash code. + + ClauseElements may have special equality comparisons which + makes us rely on them having unique hash codes for use in + hash-based collections. Stock __hash__ doesn't guarantee + unique values on platforms with moving GCs. + """ + return id(self) + def _annotate(self, values): """return a copy of this ClauseElement with the given annotations dictionary. @@ -1264,16 +1275,8 @@ class ClauseElement(Visitable): def __invert__(self): return self._negate() - if util.jython: - def __hash__(self): - """Return a distinct hash code. - - ClauseElements may have special equality comparisons which - makes us rely on them having unique hash codes for use in - hash-based collections. Stock __hash__ doesn't guarantee - unique values on platforms with moving GCs. - """ - return id(self) + def __nonzero__(self): + raise TypeError("Boolean value of this clause is not defined") def _negate(self): if hasattr(self, 'negation_clause'): @@ -1797,10 +1800,9 @@ class ColumnCollection(util.OrderedProperties): # column names in their exported columns collection existing = self[key] if not existing.shares_lineage(value): - table = getattr(existing, 'table', None) and existing.table.description util.warn(("Column %r on table %r being replaced by another " "column with the same key. Consider use_labels " - "for select() statements.") % (key, table)) + "for select() statements.") % (key, getattr(existing, 'table', None))) util.OrderedProperties.__setitem__(self, key, value) def remove(self, column): @@ -2343,7 +2345,7 @@ class _Case(ColumnElement): except TypeError: pass - if value: + if value is not None: whenlist = [ (_literal_as_binds(c).self_group(), _literal_as_binds(r)) for (c, r) in whens ] @@ -2370,19 +2372,19 @@ class _Case(ColumnElement): self.else_ = None def _copy_internals(self, clone=_clone): - if self.value: + if self.value is not None: self.value = clone(self.value) self.whens = [(clone(x), clone(y)) for x, y in self.whens] - if self.else_: + if self.else_ is not None: self.else_ = clone(self.else_) def get_children(self, **kwargs): - if self.value: + if self.value is not None: yield self.value for x, y in self.whens: yield x yield y - if self.else_: + if self.else_ is not None: yield self.else_ @property @@ -2548,7 +2550,13 @@ class _BinaryExpression(ColumnElement): self.modifiers = {} else: self.modifiers = modifiers - + + def __nonzero__(self): + try: + return self.operator(hash(self.left), hash(self.right)) + except: + raise TypeError("Boolean value of this clause is not defined") + @property def _from_objects(self): return self.left._from_objects + self.right._from_objects @@ -3017,7 +3025,7 @@ class ColumnClause(_Immutable, ColumnElement): if self.is_literal: return None - elif self.table and self.table.named_with_column: + elif self.table is not None and self.table.named_with_column: if getattr(self.table, 'schema', None): label = self.table.schema + "_" + \ _escape_for_generated(self.table.name) + "_" + \ @@ -3047,7 +3055,7 @@ class ColumnClause(_Immutable, ColumnElement): @property def _from_objects(self): - if self.table: + if self.table is not None: return [self.table] else: return [] @@ -3264,7 +3272,7 @@ class _SelectBaseMixin(object): if len(clauses) == 1 and clauses[0] is None: self._order_by_clause = ClauseList() else: - if getattr(self, '_order_by_clause', None): + if getattr(self, '_order_by_clause', None) is not None: clauses = list(self._order_by_clause) + list(clauses) self._order_by_clause = ClauseList(*clauses) @@ -3277,7 +3285,7 @@ class _SelectBaseMixin(object): if len(clauses) == 1 and clauses[0] is None: self._group_by_clause = ClauseList() else: - if getattr(self, '_group_by_clause', None): + if getattr(self, '_group_by_clause', None) is not None: clauses = list(self._group_by_clause) + list(clauses) self._group_by_clause = ClauseList(*clauses) @@ -3433,28 +3441,31 @@ class Select(_SelectBaseMixin, FromClause): self._froms = util.OrderedSet() if columns: - self._raw_columns = [ - isinstance(c, _ScalarSelect) and - c.self_group(against=operators.comma_op) or c - for c in [_literal_as_column(c) for c in columns] - ] + self._raw_columns = [] + for c in columns: + c = _literal_as_column(c) + if isinstance(c, _ScalarSelect): + c = c.self_group(against=operators.comma_op) + self._raw_columns.append(c) self._froms.update(_from_objects(*self._raw_columns)) else: self._raw_columns = [] - if whereclause: + if whereclause is not None: self._whereclause = _literal_as_text(whereclause) self._froms.update(_from_objects(self._whereclause)) else: self._whereclause = None - if from_obj: - self._froms.update( - _is_literal(f) and _TextClause(f) or f - for f in util.to_list(from_obj)) + if from_obj is not None: + for f in util.to_list(from_obj): + if _is_literal(f): + self._froms.add(_TextClause(f)) + else: + self._froms.add(f) - if having: + if having is not None: self._having = _literal_as_text(having) else: self._having = None @@ -3977,7 +3988,7 @@ class Update(_ValuesBase): _ValuesBase.__init__(self, table, values) self._bind = bind self._returning = returning - if whereclause: + if whereclause is not None: self._whereclause = _literal_as_text(whereclause) else: self._whereclause = None @@ -4027,7 +4038,7 @@ class Delete(_UpdateBase): self.table = table self._returning = returning - if whereclause: + if whereclause is not None: self._whereclause = _literal_as_text(whereclause) else: self._whereclause = None |