[1.7.x] Fix missing highlighting in some code examples

Backport of 84cafc2b35 from master

docs/topics/db/queries.txt

@@ -86,8 +86,8 @@ To save changes to an object that's already in the database, use
 Given a ``Blog`` instance ``b5`` that has already been saved to the database,
 this example changes its name and updates its record in the database::
 
-    >> b5.name = 'New name'
-    >> b5.save()
+    >>> b5.name = 'New name'
+    >>> b5.save()
 
 This performs an ``UPDATE`` SQL statement behind the scenes. Django doesn't hit
 the database until you explicitly call :meth:`~django.db.models.Model.save`.
@@ -249,9 +249,9 @@ stored, used and reused.
 
 Example::
 
-    >> q1 = Entry.objects.filter(headline__startswith="What")
-    >> q2 = q1.exclude(pub_date__gte=datetime.date.today())
-    >> q3 = q1.filter(pub_date__gte=datetime.date.today())
+    >>> q1 = Entry.objects.filter(headline__startswith="What")
+    >>> q2 = q1.exclude(pub_date__gte=datetime.date.today())
+    >>> q3 = q1.filter(pub_date__gte=datetime.date.today())
 
 These three ``QuerySets`` are separate. The first is a base
 :class:`~django.db.models.query.QuerySet` containing all entries that contain a
@@ -392,7 +392,9 @@ Basic lookups keyword arguments take the form ``field__lookuptype=value``.
 
     >>> Entry.objects.filter(pub_date__lte='2006-01-01')
 
-translates (roughly) into the following SQL::
+translates (roughly) into the following SQL:
+
+.. code-block:: sql
 
     SELECT * FROM blog_entry WHERE pub_date <= '2006-01-01';