diff options
Diffstat (limited to 'lib/sqlalchemy/sql/expression.py')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index 050b5c05b..0a5edb42f 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -428,8 +428,8 @@ def case(whens, value=None, else_=None): The expressions used for THEN and ELSE, when specified as strings, will be interpreted as bound values. To specify textual SQL expressions - for these, use the literal_column(<string>) or - text(<string>) construct. + for these, use the :func:`literal_column` + construct. The expressions used for the WHEN criterion may only be literal strings when "value" is @@ -1035,6 +1035,14 @@ def _no_literals(element): else: return element +def _only_column_elements(element): + if hasattr(element, '__clause_element__'): + element = element.__clause_element__() + if not isinstance(element, ColumnElement): + raise exc.ArgumentError("Column-based expression object expected; " + "got: %r" % element) + return element + def _corresponding_column_or_error(fromclause, column, require_embedded=False): c = fromclause.corresponding_column(column, require_embedded=require_embedded) @@ -1813,7 +1821,7 @@ class ColumnElement(ClauseElement, _CompareMixin): else: name = str(self) co = ColumnClause(self.anon_label, selectable, type_=getattr(self, 'type', None)) - + co.proxies = [self] selectable.columns[name] = co return co @@ -2428,7 +2436,7 @@ class _TextClause(Executable, ClauseElement): if self.typemap is not None and len(self.typemap) == 1: return list(self.typemap)[0] else: - return None + return sqltypes.NULLTYPE def self_group(self, against=None): if against is operators.in_op: @@ -3179,7 +3187,8 @@ class _Label(ColumnElement): self._element = element self._type = type_ self.quote = element.quote - + self.proxies = [element] + @util.memoized_property def type(self): return sqltypes.to_instance( @@ -3190,17 +3199,13 @@ class _Label(ColumnElement): def element(self): return self._element.self_group(against=operators.as_) - def _proxy_attr(name): - get = attrgetter(name) - def attr(self): - return get(self.element) - return property(attr) + @property + def primary_key(self): + return self.element.primary_key - proxies = _proxy_attr('proxies') - base_columns = _proxy_attr('base_columns') - proxy_set = _proxy_attr('proxy_set') - primary_key = _proxy_attr('primary_key') - foreign_keys = _proxy_attr('foreign_keys') + @property + def foreign_keys(self): + return self.element.foreign_keys def get_children(self, **kwargs): return self.element, @@ -3217,6 +3222,7 @@ class _Label(ColumnElement): e = self.element._make_proxy(selectable, name=self.name) else: e = column(self.name)._make_proxy(selectable=selectable) + e.proxies.append(self) return e |