def migrate():
histories = MigrationHistory.query().order(-MigrationHistory.performed_at).fetch(1)
old_version = 0
if len(histories) != 0:
old_version = histories[0].version
performed_migrations = []
funcs = [(int(name[8:]), name, f) for name, f in inspect.getmembers(sys.modules[__name__]) if name.startswith('version_')]
funcs.sort(key=lambda x: x[0])
for i, name, f in funcs:
if i <= old_version:
continue
f()
history = MigrationHistory()
history.version = i
history.performed_at = datetime.now()
history.put()
performed_migrations.append(i)
return performed_migrations
