Modernized docs in a few places

docs/patterns/sqlite3.rst

@@ -10,21 +10,21 @@ easily.
 Here is a simple example of how you can use SQLite 3 with Flask::
 
     import sqlite3
-    from flask import _app_ctx_stack
+    from flask import g
 
     DATABASE = '/path/to/database.db'
 
     def get_db():
-        top = _app_ctx_stack.top
-        if not hasattr(top, 'sqlite_db'):
-            top.sqlite_db = sqlite3.connect(DATABASE)
-        return top.sqlite_db
+        db = getattr(g, '_database', None)
+        if db is None:
+            db = g._database = connect_to_database()
+        return db
 
     @app.teardown_appcontext
     def close_connection(exception):
-        top = _app_ctx_stack.top
-        if hasattr(top, 'sqlite_db'):
-            top.sqlite_db.close()
+        db = getattr(g, '_database', None)
+        if db is not None:
+            db.close()
 
 All the application needs to do in order to now use the database is having
 an active application context (which is always true if there is an request
@@ -33,6 +33,10 @@ in flight) or to create an application context itself.  At that point the
 Whenever the context is destroyed the database connection will be
 terminated.
 
+Note: if you use Flask 0.9 or older you need to use
+``flask._app_ctx_stack.top`` instead of ``g`` as the :data:`flask.g`
+object was bound to the request and not application context.
+
 Example::
 
     @app.route('/')