improve docs for sqlite memory db

Change-Id: Icdbc13bdad3fb5ae69e79605bb7e6cb82d538c80
References: sqlalchemy#10968

lib/sqlalchemy/dialects/sqlite/pysqlite.py

@@ -51,11 +51,14 @@
     # absolute path on Windows
     e = create_engine('sqlite:///C:\\path\\to\\database.db')
 
-The sqlite ``:memory:`` identifier is the default if no filepath is
-present.  Specify ``sqlite://`` and nothing else::
+To use sqlite ``:memory:`` database specify it as the filename using
+``sqlite://:memory:``. It's also the default if no filepath is
+present, specifying only ``sqlite://`` and nothing else::
 
     # in-memory database
-    e = create_engine('sqlite://')
+    e = create_engine('sqlite://:memory:')
+    # also in-memory database
+    e2 = create_engine('sqlite://')
 
 .. _pysqlite_uri_connections:
 

lib/sqlalchemy/ext/automap.py

@@ -1006,7 +1006,7 @@ class that is produced by the :func:`.declarative.declarative_base`
     :class:`.util.Properties`, such as ``items()``, the getitem form
     is also supported::
 
-        Item = Base.classes["item"]
+        Item = Base.classes["items"]
 
     """