diff options
Diffstat (limited to 'lib/sqlalchemy/orm/strategies.py')
| -rw-r--r-- | lib/sqlalchemy/orm/strategies.py | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py index dbf99a034..23e8cb623 100644 --- a/lib/sqlalchemy/orm/strategies.py +++ b/lib/sqlalchemy/orm/strategies.py @@ -767,10 +767,17 @@ class SubqueryLoader(AbstractRelationshipLoader): if not q._from_obj and entity_mapper.isa(leftmost_mapper): q._set_select_from([entity_mapper], False) - # select from the identity columns of the outer - q._set_entities(q._adapt_col_list(leftmost_attr)) + target_cols = q._adapt_col_list(leftmost_attr) - q._distinct = True + # select from the identity columns of the outer + q._set_entities(target_cols) + + # if target_cols refer to a non-primary key or only + # part of a composite primary key, set the q as distinct + for c in target_cols: + if not set(target_cols).issuperset(c.table.primary_key): + q._distinct = True + break if q._order_by is False: q._order_by = leftmost_mapper.order_by |