objects such as Query(table.c.col) will return the "key"
+ - Added scalar() and value() methods to Query, each return a
+ single scalar value. scalar() takes no arguments and is
+ roughly equivalent to first(), value()
+ takes a single column expression and is roughly equivalent to
- 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