使用datastax Java driver for Cassandra中的带别名的chainable便利性方法选择特定列以及avg和max

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.querybuilder.QueryBuilder;
import com.datastax.driver.core.querybuilder.Select;

public class CassandraExample {
    public static void main(String[] args) {
        // 创建Cassandra集群连接
        Cluster cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
        
        // 创建会话
        Session session = cluster.connect("your_keyspace");
        
        // 创建查询构建器
        Select select = QueryBuilder.select().column("column1").as("alias1")
                                          .column("column2").as("alias2")
                                          .avg("column3").as("average")
                                          .max("column4").as("maximum")
                                  .from("your_table");
        
        // 执行查询
        ResultSet resultSet = session.execute(select);
        
        // 处理结果
        for (Row row : resultSet) {
            String alias1 = row.getString("alias1");
            String alias2 = row.getString("alias2");
            double average = row.getDouble("average");
            int maximum = row.getInt("maximum");
            
            // 打印结果
            System.out.println("Alias1: " + alias1);
            System.out.println("Alias2: " + alias2);
            System.out.println("Average: " + average);
            System.out.println("Maximum: " + maximum);
        }
        
        // 关闭会话和集群连接
        session.close();
        cluster.close();
    }
}