commit bd1d09ad762f8cf97511c5af952967e0f0caf07c
Author: Koen Deforche <koen@airwerf.lan>
Date:   Wed Sep 22 22:05:10 2010 +0200

    Fix loading with composite keys

diff --git a/src/Wt/Dbo/Session b/src/Wt/Dbo/Session
index cae0975..bd56cc1 100644
--- a/src/Wt/Dbo/Session
+++ b/src/Wt/Dbo/Session
@@ -22,6 +22,7 @@ namespace Wt {
   namespace Dbo {
     namespace Impl {
       extern WTDBO_API std::string quoteSchemaDot(const std::string& table);
+      template <class C, typename T> struct LoadHelper;
     }
 
 struct NullType {
@@ -417,6 +418,11 @@ private:
   template <class C> ptr<C> loadLazy(const typename dbo_traits<C>::IdType& id);
   template <class C> ptr<C> load(SqlStatement *statement, int& column);
 
+  template <class C>
+    ptr<C> loadWithNaturalId(SqlStatement *statement, int& column);
+  template <class C>
+    ptr<C> loadWithLongLongId(SqlStatement *statement, int& column);
+
   void prune(MetaDboBase *obj);
   template <class C> void prune(MetaDbo<C> *obj);
 
@@ -468,6 +474,7 @@ private:
   friend class DropSchema;
   friend class ToAnysAction;
   friend class FromAnyAction;
+  template <class C, typename T> friend class Impl::LoadHelper;
 };
 
   }
diff --git a/src/Wt/Dbo/Session_impl.h b/src/Wt/Dbo/Session_impl.h
index d9b8c44..ee9d727 100644
--- a/src/Wt/Dbo/Session_impl.h
+++ b/src/Wt/Dbo/Session_impl.h
@@ -15,6 +15,27 @@
 
 namespace Wt {
   namespace Dbo {
+    namespace Impl {
+      template <class C, typename T>
+      struct LoadHelper
+      {
+	static ptr<C> load(Session *session, SqlStatement *statement,
+			   int& column)
+	{
+	  return session->loadWithNaturalId<C>(statement, column);
+	};
+      };
+
+      template <class C>
+      struct LoadHelper<C, long long>
+      {
+	static ptr<C> load(Session *session, SqlStatement *statement,
+			   int& column)
+	{
+	  return session->loadWithLongLongId<C>(statement, column);
+	}
+      };
+    }
 
 template <class C>
 void Session::mapClass(const char *tableName)
@@ -78,17 +99,49 @@ Session::Mapping<C> *Session::getMapping() const
 template <class C>
 ptr<C> Session::load(SqlStatement *statement, int& column)
 {
+  return Impl::LoadHelper<C, typename dbo_traits<C>::IdType>
+    ::load(this, statement, column);
+}
+
+template <class C>
+ptr<C> Session::loadWithNaturalId(SqlStatement *statement, int& column)
+{
+  Mapping<C> *mapping = getMapping<C>();
+
+  typedef typename dbo_traits<C>::IdType IdType;
+  IdType id;
+
+  /* Natural id is possibly multiple fields anywhere */
+
+  MetaDbo<C> *dbo = new MetaDbo<C>(dbo_traits<C>::invalidId(), -1,
+				   MetaDboBase::Persisted, *this, 0);
+  implLoad<C>(*dbo, statement, column);
+
+  typename Mapping<C>::Registry::iterator i
+    = mapping->registry_.find(dbo->id());
+
+  if (i == mapping->registry_.end()) {
+    mapping->registry_[id] = dbo;
+    return ptr<C>(dbo);
+  } else {
+    delete dbo;
+    return ptr<C>(i->second);
+  }
+}
+
+template <class C>
+ptr<C> Session::loadWithLongLongId(SqlStatement *statement, int& column)
+{
   Mapping<C> *mapping = getMapping<C>();
 
   /*
-   * If mapping uses surrogate keys, then we can first read the id and decide
-   * if we already have it.
+   * If mapping uses surrogate keys, then we can first read the id and
+   * decide if we already have it.
    *
-   * If not, then we need to first read the object, get the id, and if we already
-   * had it, delete the redundant copy.
+   * If not, then we need to first read the object, get the id, and if
+   * we already had it, delete the redundant copy.
    */
-  typedef typename dbo_traits<C>::IdType IdType;
-  IdType id;
+  long long id;
 
   if (mapping->surrogateIdFieldName) {
     /* Auto-generated surrogate key is first field */
@@ -111,7 +164,6 @@ ptr<C> Session::load(SqlStatement *statement, int& column)
     }
   } else {
     /* Natural id is possibly multiple fields anywhere */
-
     MetaDbo<C> *dbo = new MetaDbo<C>(dbo_traits<C>::invalidId(), -1,
 				     MetaDboBase::Persisted, *this, 0);
     implLoad<C>(*dbo, statement, column);
diff --git a/test/dbo/DboTest.C b/test/dbo/DboTest.C
index 1fc9045..d3ceedd 100644
--- a/test/dbo/DboTest.C
+++ b/test/dbo/DboTest.C
@@ -218,6 +218,12 @@ public:
   As    asManyToOne;
   Cs    csManyToMany;
 
+  D() { }
+  D(const Coordinate& anId, const std::string& aName)
+    : id(anId),
+      name(aName)
+  { }
+
   template <class Action>
   void persist(Action& a)
   {
@@ -903,6 +909,12 @@ void DboTest::test12()
     {
       dbo::Transaction t(*session_);
 
+      session_->add(new D(Coordinate(5, 6), "yes"));
+      dbo::ptr<D> d1 = session_->find<D>();
+
+      BOOST_REQUIRE(d1->name == "yes");
+      BOOST_REQUIRE(d1->id == Coordinate(5, 6));
+
       session_->add(new C("c1"));
 
       dbo::Query< dbo::ptr<C> > query = session_->find<C>();