code: func (t *Transaction) SelectNullFloat(query string, args ...interface{}) (sql.NullFloat64, error) {
  	if t.dbmap.ExpandSliceArgs {
  		expandSliceArgs(&query, args...)
  	}
  
  	return SelectNullFloat(t, query, args...)
  }
docs: // SelectNullFloat is a convenience wrapper around the gorp.SelectNullFloat function.