package com.jpzhutech.select;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class SelectTest {

    public static void main(String[] args) {

        Connection connection = null;

        Statement statement = null;

        try {

            //String url = "jdbc:mysql://192.168.101.44/amon";

            String url = "jdbc:postgresql://192.168.100.120:5432/postgres";//换成自己PostgreSQL数据库实例所在的ip地址，并设置自己的端口

            //String user = "root";

            String user = "postgres";

            //String password = "560128";

            String password = "";  //在这里我的密码为空，读者可以自己选择是否设置密码

            //Class.forName("com.mysql.jdbc.Driver");

            Class.forName("org.postgresql.Driver");  //一定要注意和上面的MySQL语法不同

            connection= DriverManager.getConnection(url, user, password);

            System.out.println("是否成功连接pg数据库"+connection);

            String sql = "select * from student";

            statement = connection.createStatement();

            /**

             * 关于ResultSet的理解：Java程序中数据库查询结果的展现形式，或者说得到了一个结果集的表

             * 在文档的开始部分有详细的讲解该接口中应该注意的问题，请阅读JDK

             * */

            ResultSet resultSet = statement.executeQuery(sql);

            while(resultSet.next()){

                 //取出列值

                int id = resultSet.getInt(1);

                String name = resultSet.getString(2);

                System.out.println(id+","+name+",");

            }

        } catch (Exception e) {

            throw new RuntimeException(e);

        }finally{

            try {

                statement.close();

            } catch (SQLException e) {

                e.printStackTrace();

                throw new RuntimeException(e);

            }finally{

                try {

                    connection.close();

                } catch (SQLException e) {

                    e.printStackTrace();

                    throw new RuntimeException(e);

                }

            }

        }

    }

}