new file mode 100644
--- /dev/null
+++ b/examples/trac/trac/upgrades/db13.py
@@ -0,0 +1,60 @@
+sql = [
+#-- Add ticket_type to 'ticket', remove the unused 'url' column
+"""CREATE TEMPORARY TABLE ticket_old AS SELECT * FROM ticket;""",
+"""DROP TABLE ticket;""",
+"""CREATE TABLE ticket (
+        id              integer PRIMARY KEY,
+        type            text,           -- the nature of the ticket
+        time            integer,        -- the time it was created
+        changetime      integer,
+        component       text,
+        severity        text,
+        priority        text,
+        owner           text,           -- who is this ticket assigned to
+        reporter        text,
+        cc              text,           -- email addresses to notify
+        version         text,           --
+        milestone       text,           --
+        status          text,
+        resolution      text,
+        summary         text,           -- one-line summary
+        description     text,           -- problem description (long)
+        keywords        text
+);""",
+"""INSERT INTO ticket(id, type, time, changetime, component, severity, priority,
+                   owner, reporter, cc, version, milestone, status, resolution,
+                   summary, description, keywords)
+  SELECT id, 'defect', time, changetime, component, severity, priority, owner,
+         reporter, cc, version, milestone, status, resolution, summary,
+         description, keywords FROM ticket_old
+  WHERE COALESCE(severity,'') <> 'enhancement';""",
+"""INSERT INTO ticket(id, type, time, changetime, component, severity, priority,
+                   owner, reporter, cc, version, milestone, status, resolution,
+                   summary, description, keywords)
+  SELECT id, 'enhancement', time, changetime, component, 'normal', priority,
+         owner, reporter, cc, version, milestone, status, resolution, summary,
+         description, keywords FROM ticket_old
+  WHERE severity = 'enhancement';""",
+"""INSERT INTO enum (type, name, value) VALUES ('ticket_type', 'defect', '1');""",
+"""INSERT INTO enum (type, name, value) VALUES ('ticket_type', 'enhancement', '2');""",
+"""INSERT INTO enum (type, name, value) VALUES ('ticket_type', 'task', '3');""",
+"""DELETE FROM enum WHERE type = 'severity' AND name = 'enhancement';""",
+"""DROP TABLE ticket_old;""",
+]
+
+def do_upgrade(env, ver, cursor):
+    for s in sql:
+        cursor.execute(s)
+
+    # -- upgrade reports (involve a rename)
+    cursor.execute("SELECT id,sql FROM report")
+    reports = {}
+    for id, rsql in cursor:
+        reports[id] = rsql
+    for id, rsql in reports.items():
+        parts = rsql.split('ORDER BY', 1)
+        ending = len(parts)>1 and 'ORDER BY'+parts[1] or ''
+        cursor.execute("UPDATE report SET sql=%s WHERE id=%s",
+                       (parts[0].replace('severity,',
+                                         't.type AS type, severity,') + ending,
+                        id))