clarification to detached state

diff --git a/doc/build/content/unitofwork.txt b/doc/build/content/unitofwork.txt
index d13c6e82399da1fb5ab9f0fa748ec72b35fe5245..9d0e732f9d57e9cf007d023d30adafa4bb5b9756 100644 (file)
--- a/doc/build/content/unitofwork.txt
+++ b/doc/build/content/unitofwork.txt
@@ -28,7 +28,7 @@ When dealing with mapped instances with regards to Sessions, an instance may be
 
 * *Persistent* - a persistent instance has a database identity and a corresponding record in the database, and is also associated with a particular Session.   By "database identity" we mean the object is associated with a table or relational concept in the database combined with a particular primary key in that table.  Objects that are loaded by SQLAlchemy in the context of a particular session are automatically considered persistent, as are formerly pending instances which have been subject to a session `flush()`.
 
-* *Detached* - a detached instance is an instance which has a database identity and corresponding row in the database, but is not attached to any Session.  This occurs when an instance has been removed from a Session, either because the session itself was cleared or closed, or the instance was explicitly removed from the Session.  The object can be re-attached with a session again in which case it becomes Persistent again.  Detached instances are useful when an application needs to represent a long-running operation across multiple Sessions, needs to store an object in a serialized state and then restore it later (such as within an HTTP "session" object), or in some cases where code needs to load instances locally which will later be associated with some other Session.
+* *Detached* - a detached instance is an instance which has a database identity and corresponding row in the database, but is not attached to any Session.  This occurs when an instance has been removed from a Session, either because the session itself was cleared or closed, or the instance was explicitly removed from the Session.  The object can be re-attached to a session in which case it becomes Persistent again; any un-persisted changes that exist on the instance, whether they occurred during its previous persistent state or during its detached state will be detected and maintained by the new session.  Detached instances are useful when an application needs to represent a long-running operation across multiple Sessions, needs to store an object in a serialized state and then restore it later (such as within an HTTP "session" object), or in some cases where code needs to load instances locally which will later be associated with some other Session.
 
 ### Acquiring a Session {@name=getting}