diff -r ca63b6776231 -r b55754aa4f96 iro/model/session.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/iro/model/session.py	Sat Jan 28 13:02:07 2012 +0100
@@ -0,0 +1,8 @@
+from sqlalchemy.orm.session import Session
+
+from .schema import Offer
+
+class IroSession(Session):
+    @property
+    def typs(self):
+        return self.query(Offer.typ).distinct()