1 files changed, 19 insertions, 7 deletions

diff --git a/odb/mssql/polymorphic-object-result.txx b/odb/mssql/polymorphic-object-result.txx
index e469511..53244a3 100644
--- a/odb/mssql/polymorphic-object-result.txx
+++ b/odb/mssql/polymorphic-object-result.txx
@@ -18,6 +18,13 @@ namespace odb
     polymorphic_object_result_impl<T>::
     ~polymorphic_object_result_impl ()
     {
+      invalidate ();
+    }
+
+    template <typename T>
+    void polymorphic_object_result_impl<T>::
+    invalidate ()
+    {
       change_callback_type& cc (
         statements_.root_statements ().image ().change_callback_);
 
@@ -28,10 +35,15 @@ namespace odb
       }
 
       if (image_copy_ != 0)
+      {
         object_traits::free_image (image_copy_);
+        image_copy_ = 0;
+      }
 
       if (!this->end_)
         statement_->free_result ();
+
+      statement_.reset ();
     }
 
     template <typename T>
@@ -39,7 +51,7 @@ namespace odb
     polymorphic_object_result_impl (const query_base&,
                                     details::shared_ptr<select_statement> st,
                                     statements_type& sts)
-        : base_type (sts.connection ().database ()),
+        : base_type (sts.connection ()),
           statement_ (st),
           statements_ (sts),
           use_copy_ (false),
@@ -62,7 +74,6 @@ namespace odb
       assert (!rsts.locked ());
       typename statements_type::auto_lock l (rsts);
 
-      odb::database& db (this->database ());
       image_type& i (use_copy_ ? *image_copy_ : statements_.image ());
       typename root_traits::image_type& ri (
         use_copy_ ? object_traits::root_image (i) : rsts.image ());
@@ -99,7 +110,8 @@ namespace odb
         // Insert it as a root pointer (for non-unique pointers, rp should
         // still be valid and for unique pointers this is a no-op).
         //
-        ig.reset (object_traits::pointer_cache_traits::insert (db, id, rp));
+        ig.reset (
+          object_traits::pointer_cache_traits::insert (this->db_, id, rp));
 
         pobj = &pointer_traits::get_ref (p);
         current (p);
@@ -120,9 +132,9 @@ namespace odb
       }
 
       callback_event ce (callback_event::pre_load);
-      pi.dispatch (info_type::call_callback, db, pobj, &ce);
+      pi.dispatch (info_type::call_callback, this->db_, pobj, &ce);
 
-      object_traits::init (*pobj, i, &db);
+      object_traits::init (*pobj, i, &this->db_);
 
       // If we are using a copy, make sure the callback information for
       // long data also comes from the copy.
@@ -153,14 +165,14 @@ namespace odb
       if (&pi != &object_traits::info)
       {
         std::size_t d (object_traits::depth);
-        pi.dispatch (info_type::call_load, db, pobj, &d);
+        pi.dispatch (info_type::call_load, this->db_, pobj, &d);
       };
 
       rsts.load_delayed ();
       l.unlock ();
 
       ce = callback_event::post_load;
-      pi.dispatch (info_type::call_callback, db, pobj, &ce);
+      pi.dispatch (info_type::call_callback, this->db_, pobj, &ce);
       ig.release ();
     }