Polymorphic inheritance support

23 files changed, 1600 insertions, 563 deletions

diff --git a/odb/mssql/binding.hxx b/odb/mssql/binding.hxx
index 48f9679..1bbf258 100644
--- a/odb/mssql/binding.hxx
+++ b/odb/mssql/binding.hxx
@@ -24,6 +24,8 @@ namespace odb
       typedef mssql::bind bind_type;
       typedef mssql::change_callback change_callback_type;
 
+      binding (): bind (0), count (0), version (0), change_callback (0) {}
+
       binding (bind_type* b, std::size_t n)
         : bind (b), count (n), version (0), change_callback (0)
       {
diff --git a/odb/mssql/forward.hxx b/odb/mssql/forward.hxx
index ce16097..5fbaacf 100644
--- a/odb/mssql/forward.hxx
+++ b/odb/mssql/forward.hxx
@@ -38,7 +38,13 @@ namespace odb
     class object_statements;
 
     template <typename T>
-    class object_statements_no_id;
+    class polymorphic_root_object_statements;
+
+    template <typename T>
+    class polymorphic_derived_object_statements;
+
+    template <typename T>
+    class no_id_object_statements;
 
     template <typename T>
     class view_statements;
diff --git a/odb/mssql/makefile b/odb/mssql/makefile
index e4c62d5..7357eb6 100644
--- a/odb/mssql/makefile
+++ b/odb/mssql/makefile
@@ -4,21 +4,21 @@
 
 include $(dir $(lastword $(MAKEFILE_LIST)))../../build/bootstrap.make
 
-cxx :=                    \
-auto-handle.cxx           \
-connection.cxx            \
-connection-factory.cxx    \
-database.cxx              \
-error.cxx                 \
-exceptions.cxx            \
-object-statements.cxx     \
-query.cxx                 \
-query-const-expr.cxx      \
-statement.cxx             \
-statements-base.cxx       \
-tracer.cxx                \
-traits.cxx                \
-transaction.cxx           \
+cxx :=                       \
+auto-handle.cxx              \
+connection.cxx               \
+connection-factory.cxx       \
+database.cxx                 \
+error.cxx                    \
+exceptions.cxx               \
+query.cxx                    \
+query-const-expr.cxx         \
+simple-object-statements.cxx \
+statement.cxx                \
+statements-base.cxx          \
+tracer.cxx                   \
+traits.cxx                   \
+transaction.cxx              \
 transaction-impl.cxx
 
 
diff --git a/odb/mssql/no-id-object-result.hxx b/odb/mssql/no-id-object-result.hxx
new file mode 100644
index 0000000..d0246aa
--- /dev/null
+++ b/odb/mssql/no-id-object-result.hxx
@@ -0,0 +1,79 @@
+// file      : odb/mssql/no-id-object-result.hxx
+// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#ifndef ODB_MSSQL_NO_ID_OBJECT_RESULT_HXX
+#define ODB_MSSQL_NO_ID_OBJECT_RESULT_HXX
+
+#include <odb/pre.hxx>
+
+#include <cstddef> // std::size_t
+
+#include <odb/no-id-object-result.hxx>
+
+#include <odb/details/shared-ptr.hxx>
+
+#include <odb/mssql/version.hxx>
+#include <odb/mssql/forward.hxx> // query
+#include <odb/mssql/statement.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    class no_id_object_result_impl: public odb::no_id_object_result_impl<T>
+    {
+    public:
+      typedef odb::no_id_object_result_impl<T> base_type;
+
+      typedef typename base_type::object_type object_type;
+      typedef typename base_type::object_traits object_traits;
+
+      typedef typename base_type::pointer_type pointer_type;
+      typedef typename base_type::pointer_traits pointer_traits;
+
+      typedef typename object_traits::statements_type statements_type;
+
+      virtual
+      ~no_id_object_result_impl ();
+
+      no_id_object_result_impl (const query&,
+                                details::shared_ptr<select_statement>,
+                                statements_type&);
+
+      virtual void
+      load (object_type&);
+
+      virtual void
+      next ();
+
+      virtual void
+      cache ();
+
+      virtual std::size_t
+      size ();
+
+      using base_type::current;
+
+    private:
+      typedef mssql::change_callback change_callback_type;
+
+      static void
+      change_callback (void* context);
+
+    private:
+      details::shared_ptr<select_statement> statement_;
+      statements_type& statements_;
+      bool can_load_;
+      bool use_copy_;
+      typename object_traits::image_type* image_copy_;
+    };
+  }
+}
+
+#include <odb/mssql/no-id-object-result.txx>
+
+#include <odb/post.hxx>
+
+#endif // ODB_MSSQL_NO_ID_OBJECT_RESULT_HXX
diff --git a/odb/mssql/no-id-object-result.txx b/odb/mssql/no-id-object-result.txx
new file mode 100644
index 0000000..f3674fb
--- /dev/null
+++ b/odb/mssql/no-id-object-result.txx
@@ -0,0 +1,142 @@
+// file      : odb/mssql/no-id-object-result.txx
+// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#include <odb/callback.hxx>
+#include <odb/exceptions.hxx> // result_not_cached
+
+#include <odb/mssql/exceptions.hxx> // long_data_reload
+#include <odb/mssql/no-id-object-statements.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    no_id_object_result_impl<T>::
+    ~no_id_object_result_impl ()
+    {
+      change_callback_type& cc (statements_.image ().change_callback_);
+
+      if (cc.context == this)
+      {
+        cc.context = 0;
+        cc.callback = 0;
+      }
+
+      if (!this->end_)
+        statement_->free_result ();
+
+      delete image_copy_;
+    }
+
+    template <typename T>
+    no_id_object_result_impl<T>::
+    no_id_object_result_impl (const query&,
+                              details::shared_ptr<select_statement> statement,
+                              statements_type& statements)
+        : base_type (statements.connection ().database ()),
+          statement_ (statement),
+          statements_ (statements),
+          use_copy_ (false),
+          image_copy_ (0)
+    {
+    }
+
+    template <typename T>
+    void no_id_object_result_impl<T>::
+    load (object_type& obj)
+    {
+      if (!can_load_)
+        throw long_data_reload ();
+
+      odb::database& db (this->database ());
+
+      object_traits::callback (db, obj, callback_event::pre_load);
+
+      object_traits::init (obj,
+                           use_copy_ ? *image_copy_ : statements_.image (),
+                           &db);
+
+      // If we are using a copy, make sure the callback information for
+      // long data also comes from the copy.
+      //
+      can_load_ = !statement_->stream_result (
+        use_copy_ ? &statements_.image () : 0,
+        use_copy_ ? image_copy_ : 0);
+
+      object_traits::callback (db, obj, callback_event::post_load);
+    }
+
+    template <typename T>
+    void no_id_object_result_impl<T>::
+    next ()
+    {
+      can_load_ = true;
+      this->current (pointer_type ());
+
+      typename object_traits::image_type& im (statements_.image ());
+      change_callback_type& cc (im.change_callback_);
+
+      if (cc.context == this)
+      {
+        cc.callback = 0;
+        cc.context = 0;
+      }
+
+      use_copy_ = false;
+
+      if (im.version != statements_.select_image_version ())
+      {
+        binding& b (statements_.select_image_binding ());
+        object_traits::bind (b.bind, im, statement_select);
+        statements_.select_image_version (im.version);
+        b.version++;
+      }
+
+      if (statement_->fetch () == select_statement::no_data)
+      {
+        statement_->free_result ();
+        this->end_ = true;
+      }
+      else
+      {
+        cc.callback = &change_callback;
+        cc.context = this;
+      }
+    }
+
+    template <typename T>
+    void no_id_object_result_impl<T>::
+    cache ()
+    {
+    }
+
+    template <typename T>
+    std::size_t no_id_object_result_impl<T>::
+    size ()
+    {
+      throw result_not_cached ();
+    }
+
+    template <typename T>
+    void no_id_object_result_impl<T>::
+    change_callback (void* c)
+    {
+      no_id_object_result_impl<T>* r (
+        static_cast<no_id_object_result_impl<T>*> (c));
+
+      typename object_traits::image_type im (r->statements_.image ());
+
+      if (r->image_copy_ == 0)
+        r->image_copy_ = new typename object_traits::image_type (im);
+      else
+        *r->image_copy_ = im;
+
+      im.change_callback_.callback = 0;
+      im.change_callback_.context = 0;
+
+      r->use_copy_ = true;
+    }
+  }
+}
diff --git a/odb/mssql/no-id-object-statements.hxx b/odb/mssql/no-id-object-statements.hxx
new file mode 100644
index 0000000..468b632
--- /dev/null
+++ b/odb/mssql/no-id-object-statements.hxx
@@ -0,0 +1,133 @@
+// file      : odb/mssql/no-id-object-statements.hxx
+// copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#ifndef ODB_MSSQL_NO_ID_OBJECT_STATEMENTS_HXX
+#define ODB_MSSQL_NO_ID_OBJECT_STATEMENTS_HXX
+
+#include <odb/pre.hxx>
+
+#include <cstddef> // std::size_t
+
+#include <odb/forward.hxx>
+#include <odb/traits.hxx>
+
+#include <odb/details/shared-ptr.hxx>
+
+#include <odb/mssql/version.hxx>
+#include <odb/mssql/forward.hxx>
+#include <odb/mssql/mssql-types.hxx>
+#include <odb/mssql/binding.hxx>
+#include <odb/mssql/statement.hxx>
+#include <odb/mssql/statements-base.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    //
+    // Implementation for objects without object id.
+    //
+
+    template <typename T>
+    class no_id_object_statements: public statements_base
+    {
+    public:
+      typedef T object_type;
+      typedef odb::object_traits<object_type> object_traits;
+      typedef typename object_traits::pointer_type pointer_type;
+      typedef typename object_traits::image_type image_type;
+
+      typedef mssql::insert_statement insert_statement_type;
+
+    public:
+      no_id_object_statements (connection_type&);
+
+      virtual
+      ~no_id_object_statements ();
+
+      // Object image.
+      //
+      image_type&
+      image ()
+      {
+        return image_;
+      }
+
+      // Insert binding.
+      //
+      std::size_t
+      insert_image_version () const { return insert_image_version_;}
+
+      void
+      insert_image_version (std::size_t v) {insert_image_version_ = v;}
+
+      binding&
+      insert_image_binding () {return insert_image_binding_;}
+
+      // Select binding (needed for query support).
+      //
+      std::size_t
+      select_image_version () const { return select_image_version_;}
+
+      void
+      select_image_version (std::size_t v) {select_image_version_ = v;}
+
+      binding&
+      select_image_binding () {return select_image_binding_;}
+
+      // Statements.
+      //
+      insert_statement_type&
+      persist_statement ()
+      {
+        if (persist_ == 0)
+          persist_.reset (
+            new (details::shared) insert_statement_type (
+              conn_,
+              object_traits::persist_statement,
+              insert_image_binding_,
+              false));
+
+        return *persist_;
+      }
+
+    public:
+      // select = total
+      // insert = total - inverse; inverse == 0 for object without id
+      //
+      static const std::size_t insert_column_count =
+        object_traits::column_count;
+
+      static const std::size_t select_column_count =
+        object_traits::column_count;
+
+    private:
+      no_id_object_statements (const no_id_object_statements&);
+      no_id_object_statements& operator= (const no_id_object_statements&);
+
+    private:
+      image_type image_;
+
+      // Select binding.
+      //
+      std::size_t select_image_version_;
+      binding select_image_binding_;
+      bind select_image_bind_[select_column_count];
+
+      // Insert binding.
+      //
+      std::size_t insert_image_version_;
+      binding insert_image_binding_;
+      bind insert_image_bind_[insert_column_count];
+
+      details::shared_ptr<insert_statement_type> persist_;
+    };
+  }
+}
+
+#include <odb/mssql/no-id-object-statements.txx>
+
+#include <odb/post.hxx>
+
+#endif // ODB_MSSQL_NO_ID_OBJECT_STATEMENTS_HXX
diff --git a/odb/mssql/no-id-object-statements.txx b/odb/mssql/no-id-object-statements.txx
new file mode 100644
index 0000000..938fff4
--- /dev/null
+++ b/odb/mssql/no-id-object-statements.txx
@@ -0,0 +1,34 @@
+// file      : odb/mssql/no-id-object-statements.txx
+// copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#include <cstring> // std::memset
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    no_id_object_statements<T>::
+    ~no_id_object_statements ()
+    {
+    }
+
+    template <typename T>
+    no_id_object_statements<T>::
+    no_id_object_statements (connection_type& conn)
+        : statements_base (conn),
+          select_image_binding_ (select_image_bind_, select_column_count),
+          insert_image_binding_ (insert_image_bind_, insert_column_count)
+    {
+      image_.version = 0;
+      select_image_version_ = 0;
+      insert_image_version_ = 0;
+
+      select_image_binding_.change_callback = image_.change_callback ();
+
+      std::memset (insert_image_bind_, 0, sizeof (insert_image_bind_));
+      std::memset (select_image_bind_, 0, sizeof (select_image_bind_));
+    }
+  }
+}
diff --git a/odb/mssql/object-result.hxx b/odb/mssql/object-result.hxx
deleted file mode 100644
index 703b639..0000000
--- a/odb/mssql/object-result.hxx
+++ /dev/null
@@ -1,127 +0,0 @@
-// file      : odb/mssql/object-result.hxx
-// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
-// license   : ODB NCUEL; see accompanying LICENSE file
-
-#ifndef ODB_MSSQL_OBJECT_RESULT_HXX
-#define ODB_MSSQL_OBJECT_RESULT_HXX
-
-#include <odb/pre.hxx>
-
-#include <cstddef> // std::size_t
-
-#include <odb/details/shared-ptr.hxx>
-
-#include <odb/mssql/version.hxx>
-#include <odb/mssql/forward.hxx> // query, object_statements
-#include <odb/mssql/result.hxx>
-#include <odb/mssql/statement.hxx>
-
-namespace odb
-{
-  namespace mssql
-  {
-    template <typename T>
-    class object_result_impl: public odb::object_result_impl<T>
-    {
-    public:
-      typedef odb::object_result_impl<T> base_type;
-
-      typedef typename base_type::object_type object_type;
-      typedef typename base_type::object_traits object_traits;
-      typedef typename base_type::id_type id_type;
-
-      typedef typename base_type::pointer_type pointer_type;
-      typedef typename base_type::pointer_traits pointer_traits;
-
-      virtual
-      ~object_result_impl ();
-
-      object_result_impl (const query&,
-                          details::shared_ptr<select_statement>,
-                          object_statements<object_type>&);
-
-      virtual void
-      load (object_type&, bool fetch);
-
-      virtual id_type
-      load_id ();
-
-      virtual void
-      next ();
-
-      virtual void
-      cache ();
-
-      virtual std::size_t
-      size ();
-
-      using base_type::current;
-
-    private:
-      typedef mssql::change_callback change_callback_type;
-
-      static void
-      change_callback (void* context);
-
-    private:
-      details::shared_ptr<select_statement> statement_;
-      object_statements<object_type>& statements_;
-      bool can_load_;
-      bool use_copy_;
-      typename object_traits::image_type* image_copy_;
-    };
-
-    template <typename T>
-    class object_result_impl_no_id: public odb::object_result_impl_no_id<T>
-    {
-    public:
-      typedef odb::object_result_impl_no_id<T> base_type;
-
-      typedef typename base_type::object_type object_type;
-      typedef typename base_type::object_traits object_traits;
-
-      typedef typename base_type::pointer_type pointer_type;
-      typedef typename base_type::pointer_traits pointer_traits;
-
-      virtual
-      ~object_result_impl_no_id ();
-
-      object_result_impl_no_id (const query&,
-                                details::shared_ptr<select_statement>,
-                                object_statements_no_id<object_type>&);
-
-      virtual void
-      load (object_type&);
-
-      virtual void
-      next ();
-
-      virtual void
-      cache ();
-
-      virtual std::size_t
-      size ();
-
-      using base_type::current;
-
-    private:
-      typedef mssql::change_callback change_callback_type;
-
-      static void
-      change_callback (void* context);
-
-    private:
-      details::shared_ptr<select_statement> statement_;
-      object_statements_no_id<object_type>& statements_;
-      bool can_load_;
-      bool use_copy_;
-      typename object_traits::image_type* image_copy_;
-    };
-  }
-}
-
-#include <odb/mssql/object-result.txx>
-
-#include <odb/post.hxx>
-
-#endif // ODB_MSSQL_OBJECT_RESULT_HXX
diff --git a/odb/mssql/polymorphic-object-result.hxx b/odb/mssql/polymorphic-object-result.hxx
new file mode 100644
index 0000000..e370661
--- /dev/null
+++ b/odb/mssql/polymorphic-object-result.hxx
@@ -0,0 +1,92 @@
+// file      : odb/mssql/polymorphic-object-result.hxx
+// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#ifndef ODB_MSSQL_POLYMORPHIC_OBJECT_RESULT_HXX
+#define ODB_MSSQL_POLYMORPHIC_OBJECT_RESULT_HXX
+
+#include <odb/pre.hxx>
+
+#include <cstddef> // std::size_t
+
+#include <odb/polymorphic-object-result.hxx>
+
+#include <odb/details/shared-ptr.hxx>
+
+#include <odb/mssql/version.hxx>
+#include <odb/mssql/forward.hxx> // query
+#include <odb/mssql/statement.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    class polymorphic_object_result_impl:
+      public odb::polymorphic_object_result_impl<T>
+    {
+    public:
+      typedef odb::polymorphic_object_result_impl<T> base_type;
+
+      typedef typename base_type::object_type object_type;
+      typedef typename base_type::object_traits object_traits;
+      typedef typename base_type::id_type id_type;
+
+      typedef typename base_type::pointer_type pointer_type;
+      typedef typename base_type::pointer_traits pointer_traits;
+
+      typedef typename base_type::root_type root_type;
+      typedef typename base_type::root_traits root_traits;
+      typedef typename base_type::discriminator_type discriminator_type;
+
+      typedef typename object_traits::image_type image_type;
+      typedef typename object_traits::statements_type statements_type;
+
+      virtual
+      ~polymorphic_object_result_impl ();
+
+      polymorphic_object_result_impl (const query&,
+                                      details::shared_ptr<select_statement>,
+                                      statements_type&);
+
+      virtual void
+      load (object_type*, bool fetch);
+
+      virtual id_type
+      load_id ();
+
+      virtual discriminator_type
+      load_discriminator ();
+
+      virtual void
+      next ();
+
+      virtual void
+      cache ();
+
+      virtual std::size_t
+      size ();
+
+      using base_type::current;
+
+    private:
+      typedef mssql::change_callback change_callback_type;
+
+      static void
+      change_callback (void* context);
+
+    private:
+      details::shared_ptr<select_statement> statement_;
+      statements_type& statements_;
+      bool can_load_;
+      bool use_copy_;
+      image_type* image_copy_;
+    };
+  }
+}
+
+#include <odb/mssql/polymorphic-object-result.txx>
+
+#include <odb/post.hxx>
+
+#endif // ODB_MSSQL_POLYMORPHIC_OBJECT_RESULT_HXX
diff --git a/odb/mssql/polymorphic-object-result.txx b/odb/mssql/polymorphic-object-result.txx
new file mode 100644
index 0000000..be4a6ab
--- /dev/null
+++ b/odb/mssql/polymorphic-object-result.txx
@@ -0,0 +1,304 @@
+// file      : odb/mssql/polymorphic-object-result.txx
+// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#include <cassert>
+
+#include <odb/callback.hxx>
+#include <odb/cache-traits.hxx>
+#include <odb/exceptions.hxx> // result_not_cached
+
+#include <odb/mssql/exceptions.hxx> // long_data_reload
+#include <odb/mssql/polymorphic-object-statements.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    polymorphic_object_result_impl<T>::
+    ~polymorphic_object_result_impl ()
+    {
+      change_callback_type& cc (
+        statements_.root_statements ().image ().change_callback_);
+
+      if (cc.context == this)
+      {
+        cc.context = 0;
+        cc.callback = 0;
+      }
+
+      if (image_copy_ != 0)
+        object_traits::free_image (image_copy_);
+
+      if (!this->end_)
+        statement_->free_result ();
+    }
+
+    template <typename T>
+    polymorphic_object_result_impl<T>::
+    polymorphic_object_result_impl (const query&,
+                                    details::shared_ptr<select_statement> st,
+                                    statements_type& sts)
+        : base_type (sts.connection ().database ()),
+          statement_ (st),
+          statements_ (sts),
+          use_copy_ (false),
+          image_copy_ (0)
+    {
+    }
+
+    template <typename T>
+    void polymorphic_object_result_impl<T>::
+    load (object_type* pobj, bool)
+    {
+      if (!can_load_)
+        throw long_data_reload ();
+
+      typename statements_type::root_statements_type& rsts (
+        statements_.root_statements ());
+
+      // This is a top-level call so the statements cannot be locked.
+      //
+      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 ());
+
+      id_type id (root_traits::id (ri));
+
+      // Determine this object's dynamic type.
+      //
+      typedef typename root_traits::info_type info_type;
+      discriminator_type d (root_traits::discriminator (ri));
+
+      // Use the polymorphic_info() helper to get concrete_info if
+      // object_type is concrete and NULL if it is abstract.
+      //
+      const info_type* spi (polymorphic_info (object_traits::info));
+      const info_type& pi (
+        spi != 0 && spi->discriminator == d
+        ? *spi
+        : root_traits::map->find (d));
+
+      typedef typename root_traits::pointer_type root_pointer_type;
+      typedef typename root_traits::pointer_traits root_pointer_traits;
+
+      typename object_traits::pointer_cache_traits::insert_guard ig;
+
+      if (pobj == 0)
+      {
+        // Need to create a new instance of the dynamic type.
+        //
+        root_pointer_type rp (pi.create ());
+        pointer_type p (
+          root_pointer_traits::template static_pointer_cast<object_type> (rp));
+
+        // 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));
+
+        pobj = &pointer_traits::get_ref (p);
+        current (p);
+      }
+      else
+      {
+        // We are loading into an existing instance. If the static and
+        // dynamic types differ, then make sure the instance is at least
+        // of the dynamic type.
+        //
+        if (&pi != &object_traits::info)
+        {
+          const info_type& dpi (root_traits::map->find (typeid (*pobj)));
+
+          if (&dpi != &pi && dpi.derived (pi))
+            throw object_not_persistent (); // @@ type_mismatch ?
+        }
+      }
+
+      callback_event ce (callback_event::pre_load);
+      pi.dispatch (info_type::call_callback, db, pobj, &ce);
+
+      object_traits::init (*pobj, i, &db);
+
+      // If we are using a copy, make sure the callback information for
+      // long data also comes from the copy.
+      //
+      can_load_ = !statement_->stream_result (
+        use_copy_ ? &statements_.image () : 0,
+        use_copy_ ? image_copy_ : 0);
+
+      // Initialize the id image and binding and load the rest of the object
+      // (containers, dynamic part, etc).
+      //
+      typename object_traits::id_image_type& idi (statements_.id_image ());
+      root_traits::init (idi, id);
+
+      binding& idb (statements_.id_image_binding ());
+      if (idi.version != statements_.id_image_version () || idb.version == 0)
+      {
+        object_traits::bind (idb.bind, idi);
+        statements_.id_image_version (idi.version);
+        idb.version++;
+      }
+
+      object_traits::load_ (statements_, *pobj);
+
+      // Load the dynamic part of the object unless static and dynamic
+      // types are the same.
+      //
+      if (&pi != &object_traits::info)
+      {
+        std::size_t d (object_traits::depth);
+        pi.dispatch (info_type::call_load, db, pobj, &d);
+      };
+
+      rsts.load_delayed ();
+      l.unlock ();
+
+      ce = callback_event::post_load;
+      pi.dispatch (info_type::call_callback, db, pobj, &ce);
+      ig.release ();
+    }
+
+    template <typename T>
+    typename polymorphic_object_result_impl<T>::id_type
+    polymorphic_object_result_impl<T>::
+    load_id ()
+    {
+      typename root_traits::image_type& i (
+        use_copy_
+        ? object_traits::root_image (*image_copy_)
+        : statements_.root_statements ().image ());
+
+      return root_traits::id (i);
+    }
+
+    template <typename T>
+    typename polymorphic_object_result_impl<T>::discriminator_type
+    polymorphic_object_result_impl<T>::
+    load_discriminator ()
+    {
+      typename root_traits::image_type& i (
+        use_copy_
+        ? object_traits::root_image (*image_copy_)
+        : statements_.root_statements ().image ());
+
+      return root_traits::discriminator (i);
+    }
+
+    template <typename T, typename R>
+    struct polymorphic_image_rebind
+    {
+      // Derived type version.
+      //
+      typedef object_traits<T> traits;
+
+      static void
+      rebind (typename traits::statements_type& sts)
+      {
+        typename traits::image_type& im (sts.image ());
+
+        if (traits::check_version (sts.select_image_versions (), im))
+        {
+          binding& b (sts.select_image_binding (traits::depth));
+          traits::bind (b.bind, 0, 0, im, statement_select);
+          traits::update_version (
+            sts.select_image_versions (), im, sts.select_image_bindings ());
+        }
+      }
+    };
+
+    template <typename R>
+    struct polymorphic_image_rebind<R, R>
+    {
+      // Root type version.
+      //
+      typedef object_traits<R> traits;
+
+      static void
+      rebind (typename traits::statements_type& sts)
+      {
+        typename traits::image_type& im (sts.image ());
+
+        if (im.version != sts.select_image_version ())
+        {
+          binding& b (sts.select_image_binding ());
+          traits::bind (b.bind, im, statement_select);
+          sts.select_image_version (im.version);
+          b.version++;
+        }
+      }
+    };
+
+    template <typename T>
+    void polymorphic_object_result_impl<T>::
+    next ()
+    {
+      can_load_ = true;
+      this->current (pointer_type ());
+
+      change_callback_type& cc (
+        statements_.root_statements ().image ().change_callback_);
+
+      if (cc.context == this)
+      {
+        cc.callback = 0;
+        cc.context = 0;
+      }
+
+      use_copy_ = false;
+      polymorphic_image_rebind<object_type, root_type>::rebind (statements_);
+
+      if (statement_->fetch () == select_statement::no_data)
+      {
+        statement_->free_result ();
+        this->end_ = true;
+      }
+      else
+      {
+        cc.callback = &change_callback;
+        cc.context = this;
+      }
+    }
+
+    template <typename T>
+    void polymorphic_object_result_impl<T>::
+    cache ()
+    {
+    }
+
+    template <typename T>
+    std::size_t polymorphic_object_result_impl<T>::
+    size ()
+    {
+      throw result_not_cached ();
+    }
+
+    template <typename T>
+    void polymorphic_object_result_impl<T>::
+    change_callback (void* c)
+    {
+      polymorphic_object_result_impl<T>* r (
+        static_cast<polymorphic_object_result_impl<T>*> (c));
+      image_type& im (r->statements_.image ());
+
+      if (r->image_copy_ == 0)
+        r->image_copy_ = object_traits::clone_image (im);
+      else
+        object_traits::copy_image (*r->image_copy_, im);
+
+      typename root_traits::image_type& rim (
+        r->statements_.root_statements ().image ());
+
+      rim.change_callback_.callback = 0;
+      rim.change_callback_.context = 0;
+
+      r->use_copy_ = true;
+    }
+  }
+}
diff --git a/odb/mssql/polymorphic-object-statements.hxx b/odb/mssql/polymorphic-object-statements.hxx
new file mode 100644
index 0000000..0d70ae4
--- /dev/null
+++ b/odb/mssql/polymorphic-object-statements.hxx
@@ -0,0 +1,424 @@
+// file      : odb/mssql/polymorphic-object-statements.hxx
+// copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#ifndef ODB_MSSQL_POLYMORPHIC_OBJECT_STATEMENTS_HXX
+#define ODB_MSSQL_POLYMORPHIC_OBJECT_STATEMENTS_HXX
+
+#include <odb/pre.hxx>
+
+#include <cstddef> // std::size_t
+
+#include <odb/forward.hxx>
+#include <odb/traits.hxx>
+
+#include <odb/details/shared-ptr.hxx>
+
+#include <odb/mssql/version.hxx>
+#include <odb/mssql/forward.hxx>
+#include <odb/mssql/mssql-types.hxx>
+#include <odb/mssql/binding.hxx>
+#include <odb/mssql/statement.hxx>
+#include <odb/mssql/statements-base.hxx>
+#include <odb/mssql/simple-object-statements.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    //
+    // Implementation for polymorphic objects.
+    //
+
+    template <typename T>
+    class polymorphic_root_object_statements: public object_statements<T>
+    {
+    public:
+      typedef typename object_statements<T>::connection_type connection_type;
+      typedef typename object_statements<T>::object_traits object_traits;
+      typedef typename object_statements<T>::id_image_type id_image_type;
+
+      typedef
+      typename object_traits::discriminator_image_type
+      discriminator_image_type;
+
+      typedef
+      typename object_statements<T>::select_statement_type
+      select_statement_type;
+
+    public:
+      // Interface compatibility with derived_object_statements.
+      //
+      typedef polymorphic_root_object_statements root_statements_type;
+
+      root_statements_type&
+      root_statements ()
+      {
+        return *this;
+      }
+
+    public:
+      // Discriminator binding.
+      //
+      discriminator_image_type&
+      discriminator_image () {return discriminator_image_;}
+
+      std::size_t
+      discriminator_image_version () const
+      {return discriminator_image_version_;}
+
+      void
+      discriminator_image_version (std::size_t v)
+      {discriminator_image_version_ = v;}
+
+      binding&
+      discriminator_image_binding () {return discriminator_image_binding_;}
+
+      // Id binding for discriminator retrieval.
+      //
+      id_image_type&
+      discriminator_id_image () {return discriminator_id_image_;}
+
+      std::size_t
+      discriminator_id_image_version () const
+      {return discriminator_id_image_version_;}
+
+      void
+      discriminator_id_image_version (std::size_t v)
+      {discriminator_id_image_version_ = v;}
+
+      binding&
+      discriminator_id_image_binding ()
+      {return discriminator_id_image_binding_;}
+
+      //
+      //
+      select_statement_type&
+      find_discriminator_statement ()
+      {
+        if (find_discriminator_ == 0)
+          find_discriminator_.reset (
+            new (details::shared) select_statement_type (
+              this->conn_,
+              object_traits::find_discriminator_statement,
+              discriminator_id_image_binding_,
+              discriminator_image_binding_));
+
+        return *find_discriminator_;
+      }
+
+    public:
+      polymorphic_root_object_statements (connection_type&);
+
+      virtual
+      ~polymorphic_root_object_statements ();
+
+    public:
+      static const std::size_t id_column_count =
+        object_statements<T>::id_column_count;
+
+      static const std::size_t discriminator_column_count =
+        object_traits::discriminator_column_count;
+
+      static const std::size_t managed_optimistic_column_count =
+        object_traits::managed_optimistic_column_count;
+
+    private:
+      // Discriminator image.
+      //
+      discriminator_image_type discriminator_image_;
+      std::size_t discriminator_image_version_;
+      binding discriminator_image_binding_;
+      bind discriminator_image_bind_[discriminator_column_count +
+                                     managed_optimistic_column_count];
+
+      // Id image for discriminator retrieval (only used as a parameter).
+      //
+      id_image_type discriminator_id_image_;
+      std::size_t discriminator_id_image_version_;
+      binding discriminator_id_image_binding_;
+      bind discriminator_id_image_bind_[id_column_count];
+
+      details::shared_ptr<select_statement_type> find_discriminator_;
+    };
+
+    template <typename T>
+    class polymorphic_derived_object_statements: public statements_base
+    {
+    public:
+      typedef T object_type;
+      typedef odb::object_traits<object_type> object_traits;
+      typedef typename object_traits::id_type id_type;
+      typedef typename object_traits::pointer_type pointer_type;
+      typedef typename object_traits::id_image_type id_image_type;
+      typedef typename object_traits::image_type image_type;
+
+      typedef typename object_traits::root_type root_type;
+      typedef
+      polymorphic_root_object_statements<root_type>
+      root_statements_type;
+
+      typedef typename object_traits::base_type base_type;
+      typedef
+      typename object_traits::base_traits::statements_type
+      base_statements_type;
+
+      typedef
+      typename object_traits::container_statement_cache_type
+      container_statement_cache_type;
+
+      typedef mssql::insert_statement insert_statement_type;
+      typedef mssql::select_statement select_statement_type;
+      typedef mssql::update_statement update_statement_type;
+      typedef mssql::delete_statement delete_statement_type;
+
+      typedef typename root_statements_type::auto_lock auto_lock;
+
+    public:
+      polymorphic_derived_object_statements (connection_type&);
+
+      virtual
+      ~polymorphic_derived_object_statements ();
+
+    public:
+      // Delayed loading.
+      //
+      static void
+      delayed_loader (odb::database&, const id_type&, root_type&);
+
+    public:
+      // Root and immediate base statements.
+      //
+      root_statements_type&
+      root_statements ()
+      {
+        return root_statements_;
+      }
+
+      base_statements_type&
+      base_statements ()
+      {
+        return base_statements_;
+      }
+
+    public:
+      // Object image.
+      //
+      image_type&
+      image ()
+      {
+        return image_;
+      }
+
+      // Insert binding.
+      //
+      std::size_t
+      insert_image_version () const { return insert_image_version_;}
+
+      void
+      insert_image_version (std::size_t v) {insert_image_version_ = v;}
+
+      std::size_t
+      insert_id_binding_version () const { return insert_id_binding_version_;}
+
+      void
+      insert_id_binding_version (std::size_t v) {insert_id_binding_version_ = v;}
+
+      binding&
+      insert_image_binding () {return insert_image_binding_;}
+
+      // Update binding.
+      //
+      std::size_t
+      update_image_version () const { return update_image_version_;}
+
+      void
+      update_image_version (std::size_t v) {update_image_version_ = v;}
+
+      std::size_t
+      update_id_binding_version () const { return update_id_binding_version_;}
+
+      void
+      update_id_binding_version (std::size_t v) {update_id_binding_version_ = v;}
+
+      binding&
+      update_image_binding () {return update_image_binding_;}
+
+      // Select binding.
+      //
+      std::size_t*
+      select_image_versions () { return select_image_versions_;}
+
+      binding*
+      select_image_bindings () {return select_image_bindings_;}
+
+      binding&
+      select_image_binding (std::size_t d)
+      {
+        return select_image_bindings_[object_traits::depth - d];
+      }
+
+      // Object id binding (comes from the root statements).
+      //
+      id_image_type&
+      id_image () {return root_statements_.id_image ();}
+
+      std::size_t
+      id_image_version () const {return root_statements_.id_image_version ();}
+
+      void
+      id_image_version (std::size_t v) {root_statements_.id_image_version (v);}
+
+      binding&
+      id_image_binding () {return root_statements_.id_image_binding ();}
+
+      // Statements.
+      //
+      insert_statement_type&
+      persist_statement ()
+      {
+        if (persist_ == 0)
+          persist_.reset (
+            new (details::shared) insert_statement_type (
+              conn_,
+              object_traits::persist_statement,
+              insert_image_binding_,
+              false));
+
+        return *persist_;
+      }
+
+      select_statement_type&
+      find_statement (std::size_t d)
+      {
+        std::size_t i (object_traits::depth - d);
+        details::shared_ptr<select_statement_type>& p (find_[i]);
+
+        if (p == 0)
+          p.reset (
+            new (details::shared) select_statement_type (
+              conn_,
+              object_traits::find_statements[i],
+              root_statements_.id_image_binding (),
+              select_image_bindings_[i]));
+
+        return *p;
+      }
+
+      update_statement_type&
+      update_statement ()
+      {
+        if (update_ == 0)
+          update_.reset (
+            new (details::shared) update_statement_type (
+              conn_,
+              object_traits::update_statement,
+              update_image_binding_));
+
+        return *update_;
+      }
+
+      delete_statement_type&
+      erase_statement ()
+      {
+        if (erase_ == 0)
+          erase_.reset (
+            new (details::shared) delete_statement_type (
+              conn_,
+              object_traits::erase_statement,
+              root_statements_.id_image_binding ()));
+
+        return *erase_;
+      }
+
+      // Container statement cache.
+      //
+      container_statement_cache_type&
+      container_statment_cache ()
+      {
+        return container_statement_cache_;
+      }
+
+    public:
+      // select = total - id + base::select
+      // insert = total - inverse
+      // update = total - inverse - id - readonly
+      //
+      static const std::size_t id_column_count =
+        object_traits::id_column_count;
+
+      static const std::size_t select_column_count =
+        object_traits::column_count - id_column_count +
+        base_statements_type::select_column_count;
+
+      static const std::size_t insert_column_count =
+        object_traits::column_count - object_traits::inverse_column_count;
+
+      static const std::size_t update_column_count = insert_column_count -
+        object_traits::id_column_count - object_traits::readonly_column_count;
+
+    private:
+      polymorphic_derived_object_statements (
+        const polymorphic_derived_object_statements&);
+
+      polymorphic_derived_object_statements&
+      operator= (const polymorphic_derived_object_statements&);
+
+    private:
+      root_statements_type& root_statements_;
+      base_statements_type& base_statements_;
+
+      container_statement_cache_type container_statement_cache_;
+
+      image_type image_;
+
+      // Select binding. Here we are have an array of statements/bindings
+      // one for each depth. In other words, if we have classes root, base,
+      // and derived, then we have the following array of statements:
+      //
+      // [0] d + b + r
+      // [1] d + b
+      // [2] d
+      //
+      // Also, because we have a chain of images bound to these statements,
+      // we have an array of versions, one entry for each base plus one for
+      // our own image.
+      //
+      // A poly-abstract class only needs the first statement and in this
+      // case we have only one entry in the the bindings and statements
+      // arrays (but not versions; we still have a chain of images).
+      //
+      std::size_t select_image_versions_[object_traits::depth];
+      binding select_image_bindings_[
+        object_traits::abstract ? 1 : object_traits::depth];
+      bind select_image_bind_[select_column_count];
+
+      // Insert binding. The id binding is copied from the hierarchy root.
+      //
+      std::size_t insert_image_version_;
+      std::size_t insert_id_binding_version_;
+      binding insert_image_binding_;
+      bind insert_image_bind_[insert_column_count];
+
+      // Update binding. The id suffix binding is copied from the hierarchy
+      // root.
+      //
+      std::size_t update_image_version_;
+      std::size_t update_id_binding_version_;
+      binding update_image_binding_;
+      bind update_image_bind_[update_column_count + id_column_count];
+
+      details::shared_ptr<insert_statement_type> persist_;
+      details::shared_ptr<select_statement_type> find_[
+        object_traits::abstract ? 1 : object_traits::depth];
+      details::shared_ptr<update_statement_type> update_;
+      details::shared_ptr<delete_statement_type> erase_;
+    };
+  }
+}
+
+#include <odb/mssql/polymorphic-object-statements.txx>
+
+#include <odb/post.hxx>
+
+#endif // ODB_MSSQL_POLYMORPHIC_OBJECT_STATEMENTS_HXX
diff --git a/odb/mssql/polymorphic-object-statements.txx b/odb/mssql/polymorphic-object-statements.txx
new file mode 100644
index 0000000..87ed696
--- /dev/null
+++ b/odb/mssql/polymorphic-object-statements.txx
@@ -0,0 +1,136 @@
+// file      : odb/mssql/polymorphic-object-statements.txx
+// copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#include <cstring> // std::memset
+
+#include <odb/callback.hxx>
+#include <odb/exceptions.hxx>
+
+#include <odb/mssql/connection.hxx>
+#include <odb/mssql/transaction.hxx>
+#include <odb/mssql/statement-cache.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    //
+    // polymorphic_root_object_statements
+    //
+
+    template <typename T>
+    polymorphic_root_object_statements<T>::
+    ~polymorphic_root_object_statements ()
+    {
+    }
+
+    template <typename T>
+    polymorphic_root_object_statements<T>::
+    polymorphic_root_object_statements (connection_type& conn)
+        : object_statements<T> (conn),
+          discriminator_image_binding_ (discriminator_image_bind_,
+                                        discriminator_column_count +
+                                        managed_optimistic_column_count),
+          discriminator_id_image_binding_ (discriminator_id_image_bind_,
+                                           id_column_count)
+    {
+      discriminator_image_.version = 0;
+      discriminator_id_image_.version = 0;
+
+      discriminator_image_version_ = 0;
+      discriminator_id_image_version_ = 0;
+
+      std::memset (
+        discriminator_image_bind_, 0, sizeof (discriminator_image_bind_));
+      std::memset (
+        discriminator_id_image_bind_, 0, sizeof (discriminator_id_image_bind_));
+    }
+
+    //
+    // polymorphic_derived_object_statements
+    //
+
+    template <typename T>
+    polymorphic_derived_object_statements<T>::
+    ~polymorphic_derived_object_statements ()
+    {
+    }
+
+    template <typename T>
+    polymorphic_derived_object_statements<T>::
+    polymorphic_derived_object_statements (connection_type& conn)
+        : statements_base (conn),
+          root_statements_ (conn.statement_cache ().find_object<root_type> ()),
+          base_statements_ (conn.statement_cache ().find_object<base_type> ()),
+          container_statement_cache_ (conn),
+          insert_image_binding_ (insert_image_bind_, insert_column_count),
+          update_image_binding_ (update_image_bind_,
+                                 update_column_count + id_column_count)
+    {
+      image_.base = &base_statements_.image ();
+      image_.version = 0;
+
+      for (std::size_t i (0); i < object_traits::depth; ++i)
+        select_image_versions_[i] = 0;
+
+      for (std::size_t i (0);
+           i < (object_traits::abstract ? 1 : object_traits::depth);
+           ++i)
+      {
+        select_image_bindings_[i].bind = select_image_bind_;
+        select_image_bindings_[i].count = object_traits::find_column_counts[i];
+        select_image_bindings_[i].change_callback = 0;
+      }
+
+      // Statements other than the first one (which goes all the way to
+      // the root) can never override the image because they are used to
+      // load up the dynamic part of the object only after the static
+      // part has been loaded (and triggered the callback if necessary).
+      //
+      select_image_bindings_[0].change_callback =
+        root_statements_.image ().change_callback ();
+
+      insert_image_version_ = 0;
+      insert_id_binding_version_ = 0;
+      update_image_version_ = 0;
+      update_id_binding_version_ = 0;
+
+      std::memset (insert_image_bind_, 0, sizeof (insert_image_bind_));
+      std::memset (update_image_bind_, 0, sizeof (update_image_bind_));
+      std::memset (select_image_bind_, 0, sizeof (select_image_bind_));
+    }
+
+    template <typename T>
+    void polymorphic_derived_object_statements<T>::
+    delayed_loader (odb::database& db, const id_type& id, root_type& robj)
+    {
+      connection_type& conn (transaction::current ().connection ());
+      polymorphic_derived_object_statements& sts (
+        conn.statement_cache ().find_object<object_type> ());
+      root_statements_type& rsts (sts.root_statements ());
+
+      object_type& obj (static_cast<object_type&> (robj));
+
+      // The same code as in object_statements::load_delayed_().
+      //
+      if (!object_traits::find_ (sts, &id))
+        throw object_not_persistent ();
+
+      auto_result ar (*sts.find_[0]);
+
+      object_traits::callback (db, obj, callback_event::pre_load);
+      object_traits::init (obj, sts.image (), &db);
+      sts.find_[0]->stream_result ();
+      ar.free ();
+      object_traits::load_ (sts, obj); // Load containers, etc.
+
+      rsts.load_delayed ();
+
+      {
+        typename root_statements_type::auto_unlock u (rsts);
+        object_traits::callback (db, obj, callback_event::post_load);
+      }
+    }
+  }
+}
diff --git a/odb/mssql/result.hxx b/odb/mssql/result.hxx
deleted file mode 100644
index 1a178b3..0000000
--- a/odb/mssql/result.hxx
+++ /dev/null
@@ -1,25 +0,0 @@
-// file      : odb/mssql/result.hxx
-// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
-// license   : ODB NCUEL; see accompanying LICENSE file
-
-#ifndef ODB_MSSQL_RESULT_HXX
-#define ODB_MSSQL_RESULT_HXX
-
-#include <odb/pre.hxx>
-
-#include <odb/traits.hxx>
-#include <odb/result.hxx>
-
-#include <odb/mssql/version.hxx>
-#include <odb/mssql/forward.hxx>
-
-#include <odb/post.hxx>
-
-#endif // ODB_MSSQL_RESULT_HXX
-
-// Include result specializations so that the user code only needs
-// to include this header.
-//
-
-#include <odb/mssql/object-result.hxx>
-#include <odb/mssql/view-result.hxx>
diff --git a/odb/mssql/simple-object-result.hxx b/odb/mssql/simple-object-result.hxx
new file mode 100644
index 0000000..3fa101b
--- /dev/null
+++ b/odb/mssql/simple-object-result.hxx
@@ -0,0 +1,83 @@
+// file      : odb/mssql/simple-object-result.hxx
+// copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+#ifndef ODB_MSSQL_SIMPLE_OBJECT_RESULT_HXX
+#define ODB_MSSQL_SIMPLE_OBJECT_RESULT_HXX
+
+#include <odb/pre.hxx>
+
+#include <cstddef> // std::size_t
+
+#include <odb/simple-object-result.hxx>
+
+#include <odb/details/shared-ptr.hxx>
+
+#include <odb/mssql/version.hxx>
+#include <odb/mssql/forward.hxx> // query
+#include <odb/mssql/statement.hxx>
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    class object_result_impl: public odb::object_result_impl<T>
+    {
+    public:
+      typedef odb::object_result_impl<T> base_type;
+
+      typedef typename base_type::object_type object_type;
+      typedef typename base_type::object_traits object_traits;
+      typedef typename base_type::id_type id_type;
+
+      typedef typename base_type::pointer_type pointer_type;
+      typedef typename base_type::pointer_traits pointer_traits;
+
+      typedef typename object_traits::statements_type statements_type;
+
+      virtual
+      ~object_result_impl ();
+
+      object_result_impl (const query&,
+                          details::shared_ptr<select_statement>,
+                          statements_type&);
+
+      virtual void
+      load (object_type&, bool fetch);
+
+      virtual id_type
+      load_id ();
+
+      virtual void
+      next ();
+
+      virtual void
+      cache ();
+
+      virtual std::size_t
+      size ();
+
+      using base_type::current;
+
+    private:
+      typedef mssql::change_callback change_callback_type;
+
+      static void
+      change_callback (void* context);
+
+    private:
+      details::shared_ptr<select_statement> statement_;
+      statements_type& statements_;
+      bool can_load_;
+      bool use_copy_;
+      typename object_traits::image_type* image_copy_;
+    };
+  }
+}
+
+#include <odb/mssql/simple-object-result.txx>
+
+#include <odb/post.hxx>
+
+#endif // ODB_MSSQL_SIMPLE_OBJECT_RESULT_HXX
diff --git a/odb/mssql/object-result.txx b/odb/mssql/simple-object-result.txx
index 9f6b2d0..3606f68 100644
--- a/odb/mssql/object-result.txx
+++ b/odb/mssql/simple-object-result.txx
@@ -1,4 +1,4 @@
-// file      : odb/mssql/object-result.txx
+// file      : odb/mssql/simple-object-result.txx
 // copyright : Copyright (c) 2009-2012 Code Synthesis Tools CC
 // license   : ODB NCUEL; see accompanying LICENSE file
 
@@ -8,16 +8,12 @@
 #include <odb/exceptions.hxx> // result_not_cached
 
 #include <odb/mssql/exceptions.hxx> // long_data_reload
-#include <odb/mssql/object-statements.hxx>
+#include <odb/mssql/simple-object-statements.hxx>
 
 namespace odb
 {
   namespace mssql
   {
-    //
-    // object_result_impl
-    //
-
     template <typename T>
     object_result_impl<T>::
     ~object_result_impl ()
@@ -40,7 +36,7 @@ namespace odb
     object_result_impl<T>::
     object_result_impl (const query&,
                         details::shared_ptr<select_statement> statement,
-                        object_statements<object_type>& statements)
+                        statements_type& statements)
         : base_type (statements.connection ().database ()),
           statement_ (statement),
           statements_ (statements),
@@ -59,7 +55,7 @@ namespace odb
       // This is a top-level call so the statements cannot be locked.
       //
       assert (!statements_.locked ());
-      typename object_statements<object_type>::auto_lock l (statements_);
+      typename statements_type::auto_lock l (statements_);
 
       odb::database& db (this->database ());
       object_traits::callback (db, obj, callback_event::pre_load);
@@ -173,136 +169,5 @@ namespace odb
 
       r->use_copy_ = true;
     }
-
-    //
-    // object_result_impl_no_id
-    //
-
-    template <typename T>
-    object_result_impl_no_id<T>::
-    ~object_result_impl_no_id ()
-    {
-      change_callback_type& cc (statements_.image ().change_callback_);
-
-      if (cc.context == this)
-      {
-        cc.context = 0;
-        cc.callback = 0;
-      }
-
-      if (!this->end_)
-        statement_->free_result ();
-
-      delete image_copy_;
-    }
-
-    template <typename T>
-    object_result_impl_no_id<T>::
-    object_result_impl_no_id (const query&,
-                              details::shared_ptr<select_statement> statement,
-                              object_statements_no_id<object_type>& statements)
-        : base_type (statements.connection ().database ()),
-          statement_ (statement),
-          statements_ (statements),
-          use_copy_ (false),
-          image_copy_ (0)
-    {
-    }
-
-    template <typename T>
-    void object_result_impl_no_id<T>::
-    load (object_type& obj)
-    {
-      if (!can_load_)
-        throw long_data_reload ();
-
-      odb::database& db (this->database ());
-
-      object_traits::callback (db, obj, callback_event::pre_load);
-
-      object_traits::init (obj,
-                           use_copy_ ? *image_copy_ : statements_.image (),
-                           &db);
-
-      // If we are using a copy, make sure the callback information for
-      // long data also comes from the copy.
-      //
-      can_load_ = !statement_->stream_result (
-        use_copy_ ? &statements_.image () : 0,
-        use_copy_ ? image_copy_ : 0);
-
-      object_traits::callback (db, obj, callback_event::post_load);
-    }
-
-    template <typename T>
-    void object_result_impl_no_id<T>::
-    next ()
-    {
-      can_load_ = true;
-      this->current (pointer_type ());
-
-      typename object_traits::image_type& im (statements_.image ());
-      change_callback_type& cc (im.change_callback_);
-
-      if (cc.context == this)
-      {
-        cc.callback = 0;
-        cc.context = 0;
-      }
-
-      use_copy_ = false;
-
-      if (im.version != statements_.select_image_version ())
-      {
-        binding& b (statements_.select_image_binding ());
-        object_traits::bind (b.bind, im, statement_select);
-        statements_.select_image_version (im.version);
-        b.version++;
-      }
-
-      if (statement_->fetch () == select_statement::no_data)
-      {
-        statement_->free_result ();
-        this->end_ = true;
-      }
-      else
-      {
-        cc.callback = &change_callback;
-        cc.context = this;
-      }
-    }
-
-    template <typename T>
-    void object_result_impl_no_id<T>::
-    cache ()
-    {
-    }
-
-    template <typename T>
-    std::size_t object_result_impl_no_id<T>::
-    size ()
-    {
-      throw result_not_cached ();
-    }
-
-    template <typename T>
-    void object_result_impl_no_id<T>::
-    change_callback (void* c)
-    {
-      object_result_impl_no_id<T>* r (
-        static_cast<object_result_impl_no_id<T>*> (c));
-
-      typename object_traits::image_type im (r->statements_.image ());
-
-      if (r->image_copy_ == 0)
-        r->image_copy_ = new typename object_traits::image_type (im);
-      else
-        *r->image_copy_ = im;
-
-      im.change_callback_.callback = 0;
-      im.change_callback_.context = 0;
-
-      r->use_copy_ = true;
-    }
   }
 }
diff --git a/odb/mssql/object-statements.cxx b/odb/mssql/simple-object-statements.cxx
index 544930c..553a469 100644
--- a/odb/mssql/object-statements.cxx
+++ b/odb/mssql/simple-object-statements.cxx
@@ -1,8 +1,8 @@
-// file      : odb/mssql/object-statements.cxx
+// file      : odb/mssql/simple-object-statements.cxx
 // copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
 // license   : ODB NCUEL; see accompanying LICENSE file
 
-#include <odb/mssql/object-statements.hxx>
+#include <odb/mssql/simple-object-statements.hxx>
 
 namespace odb
 {
diff --git a/odb/mssql/object-statements.hxx b/odb/mssql/simple-object-statements.hxx
index dd63533..62d2c3c 100644
--- a/odb/mssql/object-statements.hxx
+++ b/odb/mssql/simple-object-statements.hxx
@@ -1,9 +1,9 @@
-// file      : odb/mssql/object-statements.hxx
+// file      : odb/mssql/simple-object-statements.hxx
 // copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
 // license   : ODB NCUEL; see accompanying LICENSE file
 
-#ifndef ODB_MSSQL_OBJECT_STATEMENTS_HXX
-#define ODB_MSSQL_OBJECT_STATEMENTS_HXX
+#ifndef ODB_MSSQL_SIMPLE_OBJECT_STATEMENTS_HXX
+#define ODB_MSSQL_SIMPLE_OBJECT_STATEMENTS_HXX
 
 #include <odb/pre.hxx>
 
@@ -20,6 +20,7 @@
 #include <odb/mssql/version.hxx>
 #include <odb/mssql/forward.hxx>
 #include <odb/mssql/mssql-types.hxx>
+#include <odb/mssql/binding.hxx>
 #include <odb/mssql/statement.hxx>
 #include <odb/mssql/statements-base.hxx>
 
@@ -29,24 +30,6 @@ namespace odb
 {
   namespace mssql
   {
-    template <typename T>
-    class object_statements;
-
-    template <typename T>
-    class object_statements_no_id;
-
-    template <typename T, typename ID = typename object_traits<T>::id_type>
-    struct object_statements_selector
-    {
-      typedef object_statements<T> type;
-    };
-
-    template <typename T>
-    struct object_statements_selector<T, void>
-    {
-      typedef object_statements_no_id<T> type;
-    };
-
     //
     // Implementation for objects with object id.
     //
@@ -76,16 +59,6 @@ namespace odb
         return locked_;
       }
 
-    public:
-      virtual
-      ~object_statements_base ();
-
-    protected:
-      object_statements_base (connection_type& conn)
-        : statements_base (conn), locked_ (false)
-      {
-      }
-
       struct auto_unlock
       {
         // Unlocks the statement on construction and re-locks it on
@@ -102,6 +75,16 @@ namespace odb
         object_statements_base& s_;
       };
 
+    public:
+      virtual
+      ~object_statements_base ();
+
+    protected:
+      object_statements_base (connection_type& conn)
+        : statements_base (conn), locked_ (false)
+      {
+      }
+
     protected:
       bool locked_;
     };
@@ -142,7 +125,9 @@ namespace odb
       typedef typename object_traits::image_type image_type;
       typedef typename object_traits::id_image_type id_image_type;
 
-      typedef pointer_cache_traits<pointer_type> object_cache_traits;
+      typedef
+      typename object_traits::pointer_cache_traits
+      pointer_cache_traits;
 
       typedef
       typename object_traits::container_statement_cache_type
@@ -196,12 +181,16 @@ namespace odb
 
       // Delayed loading.
       //
+      typedef void (*loader_function) (
+        odb::database&, const id_type&, object_type&);
+
       void
       delay_load (const id_type& id,
                   object_type& obj,
-                  const typename object_cache_traits::position_type& p)
+                  const typename pointer_cache_traits::position_type& p,
+                  loader_function l = 0)
       {
-        delayed_.push_back (delayed_load (id, obj, p));
+        delayed_.push_back (delayed_load (id, obj, p, l));
       }
 
       void
@@ -371,18 +360,7 @@ namespace odb
         return container_statement_cache_;
       }
 
-    private:
-      object_statements (const object_statements&);
-      object_statements& operator= (const object_statements&);
-
-    private:
-      void
-      load_delayed_ ();
-
-      void
-      clear_delayed_ ();
-
-    private:
+    public:
       // select = total
       // insert = total - inverse - managed_optimistic - auto_id
       // update = total - inverse - managed_optimistic - id - readonly
@@ -406,6 +384,17 @@ namespace odb
         object_traits::readonly_column_count;
 
     private:
+      object_statements (const object_statements&);
+      object_statements& operator= (const object_statements&);
+
+    private:
+      void
+      load_delayed_ ();
+
+      void
+      clear_delayed_ ();
+
+    private:
       container_statement_cache_type container_statement_cache_;
 
       image_type image_;
@@ -457,17 +446,21 @@ namespace odb
       //
       struct delayed_load
       {
-        typedef typename object_cache_traits::position_type position_type;
+        typedef typename pointer_cache_traits::position_type position_type;
 
         delayed_load () {}
-        delayed_load (const id_type& i, object_type& o, const position_type& p)
-            : id (i), obj (&o), pos (p)
+        delayed_load (const id_type& i,
+                      object_type& o,
+                      const position_type& p,
+                      loader_function l)
+            : id (i), obj (&o), pos (p), loader (l)
         {
         }
 
         id_type id;
         object_type* obj;
         position_type pos;
+        loader_function loader;
       };
 
       typedef std::vector<delayed_load> delayed_loads;
@@ -495,111 +488,12 @@ namespace odb
         delayed_loads& dl_;
       };
     };
-
-    //
-    // Implementation for objects without object id.
-    //
-
-    template <typename T>
-    class object_statements_no_id: public statements_base
-    {
-    public:
-      typedef T object_type;
-      typedef odb::object_traits<object_type> object_traits;
-      typedef typename object_traits::pointer_type pointer_type;
-      typedef typename object_traits::image_type image_type;
-
-      typedef mssql::insert_statement insert_statement_type;
-
-    public:
-      object_statements_no_id (connection_type&);
-
-      virtual
-      ~object_statements_no_id ();
-
-      // Object image.
-      //
-      image_type&
-      image ()
-      {
-        return image_;
-      }
-
-      // Insert binding.
-      //
-      std::size_t
-      insert_image_version () const { return insert_image_version_;}
-
-      void
-      insert_image_version (std::size_t v) {insert_image_version_ = v;}
-
-      binding&
-      insert_image_binding () {return insert_image_binding_;}
-
-      // Select binding (needed for query support).
-      //
-      std::size_t
-      select_image_version () const { return select_image_version_;}
-
-      void
-      select_image_version (std::size_t v) {select_image_version_ = v;}
-
-      binding&
-      select_image_binding () {return select_image_binding_;}
-
-      // Statements.
-      //
-      insert_statement_type&
-      persist_statement ()
-      {
-        if (persist_ == 0)
-          persist_.reset (
-            new (details::shared) insert_statement_type (
-              conn_,
-              object_traits::persist_statement,
-              insert_image_binding_,
-              false));
-
-        return *persist_;
-      }
-
-    private:
-      object_statements_no_id (const object_statements_no_id&);
-      object_statements_no_id& operator= (const object_statements_no_id&);
-
-    private:
-      // select = total
-      // insert = total - inverse; inverse == 0 for object without id
-      //
-      static const std::size_t insert_column_count =
-        object_traits::column_count;
-
-      static const std::size_t select_column_count =
-        object_traits::column_count;
-
-    private:
-      image_type image_;
-
-      // Select binding.
-      //
-      std::size_t select_image_version_;
-      binding select_image_binding_;
-      bind select_image_bind_[select_column_count];
-
-      // Insert binding.
-      //
-      std::size_t insert_image_version_;
-      binding insert_image_binding_;
-      bind insert_image_bind_[insert_column_count];
-
-      details::shared_ptr<insert_statement_type> persist_;
-    };
   }
 }
 
-#include <odb/mssql/object-statements.ixx>
-#include <odb/mssql/object-statements.txx>
+#include <odb/mssql/simple-object-statements.ixx>
+#include <odb/mssql/simple-object-statements.txx>
 
 #include <odb/post.hxx>
 
-#endif // ODB_MSSQL_OBJECT_STATEMENTS_HXX
+#endif // ODB_MSSQL_SIMPLE_OBJECT_STATEMENTS_HXX
diff --git a/odb/mssql/object-statements.ixx b/odb/mssql/simple-object-statements.ixx
index ed45eb8..2cc4405 100644
--- a/odb/mssql/object-statements.ixx
+++ b/odb/mssql/simple-object-statements.ixx
@@ -1,4 +1,4 @@
-// file      : odb/mssql/object-statements.ixx
+// file      : odb/mssql/simple-object-statements.ixx
 // copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
 // license   : ODB NCUEL; see accompanying LICENSE file
 
diff --git a/odb/mssql/object-statements.txx b/odb/mssql/simple-object-statements.txx
index 01249d9..5601fda 100644
--- a/odb/mssql/object-statements.txx
+++ b/odb/mssql/simple-object-statements.txx
@@ -1,4 +1,4 @@
-// file      : odb/mssql/object-statements.txx
+// file      : odb/mssql/simple-object-statements.txx
 // copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
 // license   : ODB NCUEL; see accompanying LICENSE file
 
@@ -81,42 +81,47 @@ namespace odb
       while (!dls.empty ())
       {
         delayed_load l (dls.back ());
-        typename object_cache_traits::insert_guard g (l.pos);
+        typename pointer_cache_traits::insert_guard g (l.pos);
         dls.pop_back ();
 
-        if (!object_traits::find_ (*this, l.id))
-          throw object_not_persistent ();
-
-        // Our find_() version delays result freeing.
-        //
-        auto_result ar (*find_);
-
-        object_traits::callback (db, *l.obj, callback_event::pre_load);
-
-        // Our calls to init/load below can result in additional delayed
-        // loads being added to the delayed_ vector. We need to process
-        // those before we call the post callback.
-        //
-        object_traits::init (*l.obj, image (), &db);
-        find_->stream_result ();
-        ar.free ();
-        object_traits::load_ (*this, *l.obj); // Load containers, etc.
-
-        if (!delayed_.empty ())
-          load_delayed_ ();
-
-        // Temporarily unlock the statement for the post_load call so that
-        // it can load objects of this type recursively. This is safe to do
-        // because we have completely loaded the current object. Also the
-        // delayed_ list is clear before the unlock and should be clear on
-        // re-lock (since a callback can only call public API functions
-        // which will make sure all the delayed loads are processed before
-        // returning).
-        //
+        if (l.loader == 0)
         {
-          auto_unlock u (*this);
-          object_traits::callback (db, *l.obj, callback_event::post_load);
+          if (!object_traits::find_ (*this, &l.id))
+            throw object_not_persistent ();
+
+          // Our find_() version delays result freeing.
+          //
+          auto_result ar (*find_);
+
+          object_traits::callback (db, *l.obj, callback_event::pre_load);
+
+          // Our calls to init/load below can result in additional delayed
+          // loads being added to the delayed_ vector. We need to process
+          // those before we call the post callback.
+          //
+          object_traits::init (*l.obj, image (), &db);
+          find_->stream_result ();
+          ar.free ();
+          object_traits::load_ (*this, *l.obj); // Load containers, etc.
+
+          if (!delayed_.empty ())
+            load_delayed_ ();
+
+          // Temporarily unlock the statement for the post_load call so that
+          // it can load objects of this type recursively. This is safe to do
+          // because we have completely loaded the current object. Also the
+          // delayed_ list is clear before the unlock and should be clear on
+          // re-lock (since a callback can only call public API functions
+          // which will make sure all the delayed loads are processed before
+          // returning).
+          //
+          {
+            auto_unlock u (*this);
+            object_traits::callback (db, *l.obj, callback_event::post_load);
+          }
         }
+        else
+          l.loader (db, l.id, *l.obj);
 
         g.release ();
       }
@@ -133,38 +138,11 @@ namespace odb
         for (typename delayed_loads::iterator i (delayed_.begin ()),
                e (delayed_.end ()); i != e; ++i)
         {
-          object_cache_traits::erase (i->pos);
+          pointer_cache_traits::erase (i->pos);
         }
       }
 
       delayed_.clear ();
     }
-
-    //
-    // object_statements_no_id
-    //
-
-    template <typename T>
-    object_statements_no_id<T>::
-    ~object_statements_no_id ()
-    {
-    }
-
-    template <typename T>
-    object_statements_no_id<T>::
-    object_statements_no_id (connection_type& conn)
-        : statements_base (conn),
-          select_image_binding_ (select_image_bind_, select_column_count),
-          insert_image_binding_ (insert_image_bind_, insert_column_count)
-    {
-      image_.version = 0;
-      select_image_version_ = 0;
-      insert_image_version_ = 0;
-
-      select_image_binding_.change_callback = image_.change_callback ();
-
-      std::memset (insert_image_bind_, 0, sizeof (insert_image_bind_));
-      std::memset (select_image_bind_, 0, sizeof (select_image_bind_));
-    }
   }
 }
diff --git a/odb/mssql/statement-cache.hxx b/odb/mssql/statement-cache.hxx
index d9476d4..9f2cb47 100644
--- a/odb/mssql/statement-cache.hxx
+++ b/odb/mssql/statement-cache.hxx
@@ -11,11 +11,11 @@
 #include <typeinfo>
 
 #include <odb/forward.hxx>
+#include <odb/traits.hxx>
 
 #include <odb/mssql/version.hxx>
+#include <odb/mssql/forward.hxx>
 #include <odb/mssql/statements-base.hxx>
-#include <odb/mssql/object-statements.hxx>
-#include <odb/mssql/view-statements.hxx>
 
 #include <odb/details/shared-ptr.hxx>
 #include <odb/details/type-info.hxx>
@@ -26,49 +26,18 @@ namespace odb
 {
   namespace mssql
   {
-    class connection;
-
     class LIBODB_MSSQL_EXPORT statement_cache
     {
     public:
-      statement_cache (connection& conn)
-          : conn_ (conn)
-      {
-      }
+      statement_cache (connection& conn): conn_ (conn) {}
 
       template <typename T>
-      typename object_statements_selector<T>::type&
-      find_object ()
-      {
-        typedef typename object_statements_selector<T>::type object_statements;
-
-        map::iterator i (map_.find (&typeid (T)));
-
-        if (i != map_.end ())
-          return static_cast<object_statements&> (*i->second);
-
-        details::shared_ptr<object_statements> p (
-          new (details::shared) object_statements (conn_));
-
-        map_.insert (map::value_type (&typeid (T), p));
-        return *p;
-      }
+      typename object_traits<T>::statements_type&
+      find_object ();
 
       template <typename T>
       view_statements<T>&
-      find_view ()
-      {
-        map::iterator i (map_.find (&typeid (T)));
-
-        if (i != map_.end ())
-          return static_cast<view_statements<T>&> (*i->second);
-
-        details::shared_ptr<view_statements<T> > p (
-          new (details::shared) view_statements<T> (conn_));
-
-        map_.insert (map::value_type (&typeid (T), p));
-        return *p;
-      }
+      find_view ();
 
     private:
       typedef std::map<const std::type_info*,
@@ -81,6 +50,8 @@ namespace odb
   }
 }
 
+#include <odb/mssql/statement-cache.txx>
+
 #include <odb/post.hxx>
 
 #endif // ODB_MSSQL_STATEMENT_CACHE_HXX
diff --git a/odb/mssql/statement-cache.txx b/odb/mssql/statement-cache.txx
new file mode 100644
index 0000000..655f861
--- /dev/null
+++ b/odb/mssql/statement-cache.txx
@@ -0,0 +1,43 @@
+// file      : odb/mssql/statement-cache.txx
+// copyright : Copyright (c) 2005-2012 Code Synthesis Tools CC
+// license   : ODB NCUEL; see accompanying LICENSE file
+
+namespace odb
+{
+  namespace mssql
+  {
+    template <typename T>
+    typename object_traits<T>::statements_type& statement_cache::
+    find_object ()
+    {
+      typedef typename object_traits<T>::statements_type statements_type;
+
+      map::iterator i (map_.find (&typeid (T)));
+
+      if (i != map_.end ())
+        return static_cast<statements_type&> (*i->second);
+
+      details::shared_ptr<statements_type> p (
+        new (details::shared) statements_type (conn_));
+
+      map_.insert (map::value_type (&typeid (T), p));
+      return *p;
+    }
+
+    template <typename T>
+    view_statements<T>& statement_cache::
+    find_view ()
+    {
+      map::iterator i (map_.find (&typeid (T)));
+
+      if (i != map_.end ())
+        return static_cast<view_statements<T>&> (*i->second);
+
+      details::shared_ptr<view_statements<T> > p (
+        new (details::shared) view_statements<T> (conn_));
+
+      map_.insert (map::value_type (&typeid (T), p));
+      return *p;
+    }
+  }
+}
diff --git a/odb/mssql/view-result.hxx b/odb/mssql/view-result.hxx
index b750ae4..a847306 100644
--- a/odb/mssql/view-result.hxx
+++ b/odb/mssql/view-result.hxx
@@ -9,11 +9,12 @@
 
 #include <cstddef> // std::size_t
 
+#include <odb/view-result.hxx>
+
 #include <odb/details/shared-ptr.hxx>
 
 #include <odb/mssql/version.hxx>
 #include <odb/mssql/forward.hxx> // query, view_statements
-#include <odb/mssql/result.hxx>
 #include <odb/mssql/statement.hxx>
 
 namespace odb
@@ -32,12 +33,14 @@ namespace odb
       typedef typename base_type::pointer_type pointer_type;
       typedef typename base_type::pointer_traits pointer_traits;
 
+      typedef view_statements<view_type> statements_type;
+
       virtual
       ~view_result_impl ();
 
       view_result_impl (const query&,
                         details::shared_ptr<select_statement>,
-                        view_statements<view_type>&);
+                        statements_type&);
 
       virtual void
       load (view_type&);
@@ -61,7 +64,7 @@ namespace odb
 
     private:
       details::shared_ptr<select_statement> statement_;
-      view_statements<view_type>& statements_;
+      statements_type& statements_;
       bool can_load_;
       bool use_copy_;
       typename view_traits::image_type* image_copy_;
diff --git a/odb/mssql/view-result.txx b/odb/mssql/view-result.txx
index a9b28a3..5058dc7 100644
--- a/odb/mssql/view-result.txx
+++ b/odb/mssql/view-result.txx
@@ -34,7 +34,7 @@ namespace odb
     view_result_impl<T>::
     view_result_impl (const query&,
                       details::shared_ptr<select_statement> statement,
-                      view_statements<view_type>& statements)
+                      statements_type& statements)
         : base_type (statements.connection ().database ()),
           statement_ (statement),
           statements_ (statements),