hibernate mysql自定义变量

Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();

String sql = "SET @age_group := 0, @prev_age := NULL; " +
             "SELECT age_group, COUNT(*) as user_count " +
             "FROM ( " +
             "    SELECT (@age_group := CASE WHEN @prev_age = age THEN @age_group ELSE @age_group + 1 END) AS age_group, " +
             "           (@prev_age := age) AS age " +
             "    FROM User " +
             "    ORDER BY age " +
             ") AS subquery " +
             "GROUP BY age_group;";

SQLQuery query = session.createSQLQuery(sql);
List<Object[]> results = query.list();

for (Object[] result : results) {
    int ageGroup = (int) result[0];
    long userCount = (long) result[1];
    System.out.println("Age Group: " + ageGroup + ", User Count: " + userCount);
}

tx.commit();
session.close();