Is it mandatory to use addScalar() in createSqlQuery() in hibernate? Why do we need to specify the Data type to hibernate while executing SQL queries?

String sql = "select Band.band_id bandId from guest_band Band";
   sessionFactory.getCurrentSession().createSQLQuery(sql)
    .addScalar("bandId", Hibernate.LONG)
    .list();

I got to know that addScalar() is used to state hibernate the DataType of the selected item, bandId in this case. But my question is, why do we need to specify the type to hibernate? What does it internally perform? Secondly is it an exception if we don't addScalar()? Lastly, is there any alternate way how this can be achieved?

via Chebli Mohamed