// update_field for template specialization
// col_binder_impl<boost::posix_time::ptime>
void update_field( void * pRecord )
{
ptime & pt = get_memvar_ref<ptime>( pRecord );
pt = ptime( date( DBVar_.year, DBVar_.month, DBVar_.day ),
time_duration( DBVar_.hour, DBVar_.minute,
DBVar_.second, DBVar_.fraction ) );
}