如何在IoTDB中统计一个SQL中每台设备下的时序个数？

import java.sql.*;

public class IoTDBExample {
    public static void main(String[] args) {
        String jdbcUrl = "jdbc:iotdb://localhost:6667/";
        String username = "root";
        String password = "root";

        try {
            // 连接到IoTDB数据库
            Class.forName("org.apache.iotdb.jdbc.IoTDBDriver");
            Connection connection = DriverManager.getConnection(jdbcUrl, username, password);

            // 编写SQL查询语句
            String sql = "SELECT count(*) FROM root GROUP BY deviceId";

            // 执行SQL查询语句
            Statement statement = connection.createStatement();
            ResultSet resultSet = statement.executeQuery(sql);

            // 解析查询结果
            while (resultSet.next()) {
                String deviceId = resultSet.getString("deviceId");
                long count = resultSet.getLong("count");

                System.out.println("设备ID：" + deviceId + "，时序个数：" + count);
            }

            // 关闭连接
            resultSet.close();
            statement.close();
            connection.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}