diff options
Diffstat (limited to 'lib/sqlalchemy/sql/expression.py')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 74 |
1 files changed, 54 insertions, 20 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index 859ee0437..939456b9a 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -1283,14 +1283,48 @@ func = _FunctionGenerator() # TODO: use UnaryExpression for this instead ? modifier = _FunctionGenerator(group=False) -class _generated_label(unicode): - """A unicode subclass used to identify dynamically generated names.""" +class _truncated_label(unicode): + """A unicode subclass used to identify symbolic " + "names that may require truncation.""" -def _escape_for_generated(x): - if isinstance(x, _generated_label): - return x + def apply_map(self, map_): + return self + +# for backwards compatibility in case +# someone is re-implementing the +# _truncated_identifier() sequence in a custom +# compiler +_generated_label = _truncated_label + +class _anonymous_label(_truncated_label): + """A unicode subclass used to identify anonymously + generated names.""" + + def __add__(self, other): + return _anonymous_label( + unicode(self) + + unicode(other)) + + def __radd__(self, other): + return _anonymous_label( + unicode(other) + + unicode(self)) + + def apply_map(self, map_): + return self % map_ + +def _as_truncated(value): + """coerce the given value to :class:`._truncated_label`. + + Existing :class:`._truncated_label` and + :class:`._anonymous_label` objects are passed + unchanged. + """ + + if isinstance(value, _truncated_label): + return value else: - return x.replace('%', '%%') + return _truncated_label(value) def _string_or_unprintable(element): if isinstance(element, basestring): @@ -2117,7 +2151,9 @@ class ColumnElement(ClauseElement, _CompareMixin): else: key = name - co = ColumnClause(name, selectable, type_=getattr(self, + co = ColumnClause(_as_truncated(name), + selectable, + type_=getattr(self, 'type', None)) co.proxies = [self] selectable._columns[key] = co @@ -2165,7 +2201,7 @@ class ColumnElement(ClauseElement, _CompareMixin): expressions and function calls. """ - return _generated_label('%%(%d %s)s' % (id(self), getattr(self, + return _anonymous_label('%%(%d %s)s' % (id(self), getattr(self, 'name', 'anon'))) class ColumnCollection(util.OrderedProperties): @@ -2588,10 +2624,10 @@ class _BindParamClause(ColumnElement): """ if unique: - self.key = _generated_label('%%(%d %s)s' % (id(self), key + self.key = _anonymous_label('%%(%d %s)s' % (id(self), key or 'param')) else: - self.key = key or _generated_label('%%(%d param)s' + self.key = key or _anonymous_label('%%(%d param)s' % id(self)) # identifiying key that won't change across @@ -2639,14 +2675,14 @@ class _BindParamClause(ColumnElement): def _clone(self): c = ClauseElement._clone(self) if self.unique: - c.key = _generated_label('%%(%d %s)s' % (id(c), c._orig_key + c.key = _anonymous_label('%%(%d %s)s' % (id(c), c._orig_key or 'param')) return c def _convert_to_unique(self): if not self.unique: self.unique = True - self.key = _generated_label('%%(%d %s)s' % (id(self), + self.key = _anonymous_label('%%(%d %s)s' % (id(self), self._orig_key or 'param')) def compare(self, other, **kw): @@ -3615,7 +3651,7 @@ class Alias(FromClause): if name is None: if self.original.named_with_column: name = getattr(self.original, 'name', None) - name = _generated_label('%%(%d %s)s' % (id(self), name + name = _anonymous_label('%%(%d %s)s' % (id(self), name or 'anon')) self.name = name @@ -3816,7 +3852,7 @@ class _Label(ColumnElement): while isinstance(element, _Label): element = element.element self.name = self.key = self._label = name \ - or _generated_label('%%(%d %s)s' % (id(self), + or _anonymous_label('%%(%d %s)s' % (id(self), getattr(element, 'name', 'anon'))) self._element = element self._type = type_ @@ -3973,11 +4009,9 @@ class ColumnClause(_Immutable, ColumnElement): elif t is not None and t.named_with_column: if getattr(t, 'schema', None): label = t.schema.replace('.', '_') + "_" + \ - _escape_for_generated(t.name) + "_" + \ - _escape_for_generated(self.name) + t.name + "_" + self.name else: - label = _escape_for_generated(t.name) + "_" + \ - _escape_for_generated(self.name) + label = t.name + "_" + self.name # ensure the label name doesn't conflict with that # of an existing column @@ -3989,7 +4023,7 @@ class ColumnClause(_Immutable, ColumnElement): counter += 1 label = _label - return _generated_label(label) + return _as_truncated(label) else: return self.name @@ -4018,7 +4052,7 @@ class ColumnClause(_Immutable, ColumnElement): # otherwise its considered to be a label is_literal = self.is_literal and (name is None or name == self.name) c = self._constructor( - name or self.name, + _as_truncated(name or self.name), selectable=selectable, type_=self.type, is_literal=is_literal |