diff options
| -rw-r--r-- | CHANGES | 6 | ||||
| -rw-r--r-- | lib/sqlalchemy/orm/query.py | 5 | ||||
| -rw-r--r-- | test/orm/query.py | 1 |
3 files changed, 12 insertions, 0 deletions
@@ -19,6 +19,12 @@ CHANGES objects such as Query(table.c.col) will return the "key" attribute of the Column. + - Added scalar() and value() methods to Query, each return a + single scalar value. scalar() takes no arguments and is + roughly equivalent to first()[0], value() + takes a single column expression and is roughly equivalent to + values(expr).next()[0]. + - Improved the determination of the FROM clause when placing SQL expressions in the query() list of entities. In particular scalar subqueries should not "leak" their inner FROM objects diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py index c9f29e6be..c2d47afea 100644 --- a/lib/sqlalchemy/orm/query.py +++ b/lib/sqlalchemy/orm/query.py @@ -550,6 +550,11 @@ class Query(object): return iter(q) _values = values + def value(self, column): + """Return a scalar result corresponding to the given column expression.""" + + return self.values(column).next()[0] + @_generative() def add_column(self, column): """Add a SQL ColumnElement to the list of result columns to be returned.""" diff --git a/test/orm/query.py b/test/orm/query.py index fb16ae780..ffc7104c8 100644 --- a/test/orm/query.py +++ b/test/orm/query.py @@ -568,6 +568,7 @@ class AggregateTest(QueryTest): sess = create_session() orders = sess.query(Order).filter(Order.id.in_([2, 3, 4])) self.assertEquals(orders.values(func.sum(Order.user_id * Order.address_id)).next(), (79,)) + self.assertEquals(orders.value(func.sum(Order.user_id * Order.address_id)), 79) def test_apply(self): sess = create_session() |