fix error reporting in evaluator for unknown clauselist operators.

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/evaluator.py b/lib/sqlalchemy/orm/evaluator.py
index 05af5d8ca..3ee70782d 100644
--- a/lib/sqlalchemy/orm/evaluator.py
+++ b/lib/sqlalchemy/orm/evaluator.py
@@ -54,7 +54,7 @@ class EvaluatorCompiler(object):
                 if has_null:
                     return None
                 return False
-        if clause.operator is operators.and_:
+        elif clause.operator is operators.and_:
             def evaluate(obj):
                 for sub_evaluate in evaluators:
                     value = sub_evaluate(obj)
@@ -63,6 +63,8 @@ class EvaluatorCompiler(object):
                             return None
                         return False
                 return True
+        else:
+            raise UnevaluatableError("Cannot evaluate clauselist with operator %s" % clause.operator)
 
         return evaluate