Template Template Parameter and Template Traits

[Peter_APIIT]

Hello to all, i have create a generic data manager which uses several data type format and different database but encountered an error to get the trait during object instantiation.

template <typename T, template <typename U> class backEndFactoryType = ClsBackEndTypeTraits >
class ClsSqlDataManager
{
public:
    ClsSqlDataManager();
    ~ClsSqlDataManager();

    int ReadData(const int&, const std::string&, soci::row&);
    int WriteData(const int&, const std::string&, soci::row&);

//typedef backEndFactoryType<U>::backEndType backEndType;

};

template <class T>
class ClsBackEndTypeTraits
{
public:
    typedef T backEndType;
};
//----------------------------------------------------------------
// Sqlite3 Back End Type Template Specialization
template <>
class ClsBackEndTypeTraits <soci::sqlite3_backend_factory>
{
public:
    typedef soci::sqlite3_backend_factory backEndType;
};

Main.cpp
ClsSqlDataManager<Json::Value, ClsBackEndTypeTraits  > db;

It cannot get the type traits defined.

Please help.

Thanks.