- the full featureset of the SelectResults extension has been merged

into a new set of methods available off of Query.  These methods
all provide "generative" behavior, whereby the Query is copied
and a new one returned with additional criterion added.
The new methods include:

  filter() - applies select criterion to the query
  filter_by() - applies "by"-style criterion to the query
  avg() - return the avg() function on the given column
  join() - join to a property (or across a list of properties)
  outerjoin() - like join() but uses LEFT OUTER JOIN
  limit()/offset() - apply LIMIT/OFFSET
  range-based access which applies limit/offset:
     session.query(Foo)[3:5]
  distinct() - apply DISTINCT
  list() - evaluate the criterion and return results

no incompatible changes have been made to Query's API and no methods
have been deprecated.  Existing methods like select(), select_by(),
get(), get_by() all execute the query at once and return results
like they always did.  join_to()/join_via() are still there although
the generative join()/outerjoin() methods are easier to use.

- the return value for multiple mappers used with instances() now returns
a cartesian product of the requested list of mappers, represented
as a list of tuples.  this corresponds to the documented behavior.
So that instances match up properly, the "uniquing" is disabled when
this feature is used.
- strings and columns can also be sent to the *args of instances() where
those exact result columns will be part of the result tuples.
- query() method is added by assignmapper.  this helps with
navigating to all the new generative methods on Query.

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/sqlalchemy/ext/assignmapper.py b/lib/sqlalchemy/ext/assignmapper.py
index 178f150e5..aee96f06e 100644
--- a/lib/sqlalchemy/ext/assignmapper.py
+++ b/lib/sqlalchemy/ext/assignmapper.py
@@ -34,6 +34,7 @@ def assign_mapper(ctx, class_, *args, **kwargs):
         extension = ctx.mapper_extension
     m = mapper(class_, extension=extension, *args, **kwargs)
     class_.mapper = m
+    class_.query = classmethod(lambda cls: Query(class_, session=ctx.current))
     for name in ['get', 'select', 'select_by', 'selectfirst', 'selectfirst_by', 'selectone', 'get_by', 'join_to', 'join_via', 'count', 'count_by', 'options', 'instances']:
         monkeypatch_query_method(ctx, class_, name)
     for name in ['flush', 'delete', 'expire', 'refresh', 'expunge', 'merge', 'save', 'update', 'save_or_update']: