- sessionmaker module is out, replaced with simple function in session.py

- scoping/class instrumenting behavior of sessionmaker moved into new scoping module
which implements scoped_session() (subject to potential name change)
- SessionContext / assignmapper are deprecated, replaced with scoped_session()

1 files changed, 6 insertions, 0 deletions

diff --git a/doc/build/content/datamapping.txt b/doc/build/content/datamapping.txt
index 6308c8d7b..37afa0fd5 100644
--- a/doc/build/content/datamapping.txt
+++ b/doc/build/content/datamapping.txt
@@ -108,6 +108,12 @@ We're now ready to start talking to the database.  The ORM's "handle" to the dat
     >>> from sqlalchemy.orm import sessionmaker
     >>> Session = sessionmaker(bind=engine, autoflush=True, transactional=True)
 
+If you don't have an `Engine` yet, but want to define `Session`, define it without `bind`, and set the `bind` parameter later:
+
+    {python}
+    >>> Session = sessionmaker(autoflush=True, transactional=True)
+    >>> Session.configure(bind=engine)  # once engine is available
+    
 This `Session` class will create new `Session` objects which are bound to our database and have some various transactional characteristics.  Whenever you need to have a conversation with the database, you instantiate a `Session`:
 
     {python}