From f9e12b99a9aef6680353d65feac3201125079e38 Mon Sep 17 00:00:00 2001
From: Konsta Vesterinen <konsta.vesterinen@gmail.com>
Date: Mon, 20 Oct 2014 12:09:56 +0300
Subject: [PATCH] Add support for InstrumentedAttributes in get_mapper

---
 sqlalchemy_utils/functions/orm.py  | 2 ++
 tests/functions/test_get_mapper.py | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/sqlalchemy_utils/functions/orm.py b/sqlalchemy_utils/functions/orm.py
index 9ff3a56..4ef8b47 100644
--- a/sqlalchemy_utils/functions/orm.py
+++ b/sqlalchemy_utils/functions/orm.py
@@ -83,6 +83,8 @@ def get_mapper(mixed):
         mixed = mixed.element
     if isinstance(mixed, AliasedInsp):
         return mixed.mapper
+    if isinstance(mixed, sa.orm.attributes.InstrumentedAttribute):
+        mixed = mixed.class_
     if isinstance(mixed, sa.Table):
         mappers = [
             mapper for mapper in mapperlib._mapper_registry
diff --git a/tests/functions/test_get_mapper.py b/tests/functions/test_get_mapper.py
index 7f75620..a282be9 100644
--- a/tests/functions/test_get_mapper.py
+++ b/tests/functions/test_get_mapper.py
@@ -42,6 +42,11 @@ class TestGetMapper(object):
             sa.inspect(self.Building)
         )
 
+    def test_instrumented_attribute(self):
+        assert (
+            get_mapper(self.Building.id) == sa.inspect(self.Building)
+        )
+
     def test_table_alias(self):
         alias = sa.orm.aliased(self.Building.__table__)
         assert (