diff options
Diffstat (limited to 'lib/sqlalchemy/sql/selectable.py')
| -rw-r--r-- | lib/sqlalchemy/sql/selectable.py | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py index bfba35de1..73341053d 100644 --- a/lib/sqlalchemy/sql/selectable.py +++ b/lib/sqlalchemy/sql/selectable.py @@ -1101,6 +1101,14 @@ class Alias(FromClause): or 'anon')) self.name = name + def self_group(self, target=None): + if isinstance(target, CompoundSelect) and \ + isinstance(self.original, Select) and \ + self.original._needs_parens_for_grouping(): + return FromGrouping(self) + + return super(Alias, self).self_group(target) + @property def description(self): if util.py3k: @@ -3208,6 +3216,13 @@ class Select(HasPrefixes, HasSuffixes, GenerativeSelect): return None return None + def _needs_parens_for_grouping(self): + return ( + self._limit_clause is not None or + self._offset_clause is not None or + bool(self._order_by_clause.clauses) + ) + def self_group(self, against=None): """return a 'grouping' construct as per the ClauseElement specification. @@ -3217,7 +3232,8 @@ class Select(HasPrefixes, HasSuffixes, GenerativeSelect): expressions and should not require explicit use. """ - if isinstance(against, CompoundSelect): + if isinstance(against, CompoundSelect) and \ + not self._needs_parens_for_grouping(): return self return FromGrouping(self) |