用Java查询sql返回结果：
package bw.jg.HelloMySql;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class SelectInfo {

    public static void main(String[] args){
        try {
            /*
             * 数据库连接
             */
            String url = "jdbc:mysql://localhost:3306/test?characterEncoding=utf-8";
            final String user = "root";
            final String password = "";
            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = DriverManager.getConnection(url, user, password);
            System.out.println("连接成功");
            
            
            Statement stmt=conn.createStatement();//创建一个Statement对象
            String sql="SELECT t.*,CASE CONCAT( a1.customer_type, a2.customer_type ) WHEN 10 THEN \'公对私交易\' WHEN 01 THEN \'私对公交易\' WHEN 11 THEN \'公对公交易\' WHEN 00 THEN \'私对私交易\' END AS trade_type FROM trade t LEFT JOIN account a1 ON t.account_id1 = a1.account_id LEFT JOIN account a2 ON t.account_id2 = a2.account_id";//生成一条sql语句
            ResultSet rs=stmt.executeQuery(sql);//执行查询，把查询结果赋值给结果集对象
            int id = 0;
            String account_id1 = null,account_id2 = null,trade_type=null;
            float amount = 0;
            System.out.println("id\t 转出账户\t\t\t 转入账户\t\t\t 金额 \t 交易类型");
            while(rs.next()) {
                id=rs.getInt(1);
                account_id1=rs.getString(2);
                account_id2=rs.getString(3);
                amount=rs.getFloat(4);
                trade_type=rs.getString(5);
                System.out.println(id+"\t"+account_id1+"\t"+account_id2+"\t"+amount+"\t"+trade_type+"\t");
            }
            System.out.println("获得查询结果集");
            conn.close();
            System.out.println("关闭数据库连接对象");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            System.out.println("引擎失败");
            e.printStackTrace();
        }
    }
}