一篇文章带你了解java数据库连接

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

conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test_demo?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC","root","password");

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CREATE TABLE `websites` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(20) NOT NULL DEFAULT '' COMMENT '站点名称',

  `url` varchar(255) NOT NULL DEFAULT '',

  `alexa` int(11) NOT NULL DEFAULT '0' COMMENT 'Alexa 排名',

  `country` char(10) NOT NULL DEFAULT '' COMMENT '国家',

  PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;

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INSERT INTO `test_demo`.`websites` (`id`, `name`, `url`, `alexa`, `country`) VALUES ('1', 'Google', 'https://www.google.cm/', '1', 'USA');

INSERT INTO `test_demo`.`websites` (`id`, `name`, `url`, `alexa`, `country`) VALUES ('2'<360>, '淘宝', 'https://www.taobao.com/', '13', 'CN');

INSERT INTO `test_demo`.`websites` (`id`, `name`, `url`, `alexa`, `country`) VALUES ('3', 'java入门', 'https://blog.csdn.net/wwwzhouzy/category_11249888.html', '5892', '');

INSERT INTO `test_demo`.`websites` (`id`, `name`, `url`, `alexa`, `country`) VALUES ('4', '微博', 'http://weibo.com/', '20', 'CN');

INSERT INTO `test_demo`.`websites` (`id`, `name`, `url`, `alexa`, `country`) VALUES ('5', 'Facebook', 'https://www.facebook.com/', '3', 'USA');

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package com.zhouzy.base.t11;

import java.sql.*;

public class MysqlTest {

     // MySQL 8.0 以下版本 - JDBC 驱动名及数据库 URL

    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; 

    static final String DB_URL = "jdbc:mysql://localhost:3306/test_demo";

    // MySQL 8.0 以上版本 - JDBC 驱动名及数据库 URL

    //static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver"; 

    //static final String DB_URL = "jdbc:mysql://localhost:3306/RUNOOB?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";

    // 数据库的用户名与密码，需要根据自己的设置

    static final String USER = "root";

    static final String PASS = "123456";

    public static void main(String[] args) {

        Connection conn = null;

        Statement stmt = null;

        try{

            // 注册 JDBC 驱动

            Class.forName(JDBC_DRIVER);

            // 打开链接

            System.out.println("连接数据库...");

            conn = DriverManager.getConnection(DB_URL,USER,PASS);

            // 执行查询

            System.out.println(" 实例化Statement对象...");

            stmt = conn.createStatement();

            String sql;

            sql = "SELECT id, name, url FROM websites";

            ResultSet rs = stmt.executeQuery(sql);

            // 展开结果集数据库

            while(rs.next()){

                // 通过字段检索

                int id  = rs.getInt("id");

                String name = rs.getString("name");

                String url = rs.getString("url");

                // 输出数据

                System.out.print("ID: " + id);

                System.out.print(", 站点名称: " + name);

                System.out.print(", 站点 URL: " + url);

                System.out.print("\n");

            }

            // 完成后关闭

            rs.close();

            stmt.close();

            conn.close();

        }catch(SQLException se){

            // 处理 JDBC 错误

            se.printStackTrace();

        }catch(Exception e){

            // 处理 Class.forName 错误

            e.printStackTrace();

        }finally{

            // 关闭资源

            try{

                if(stmt!=null) stmt.close();

            }catch(SQLException se2){

            }// 什么都不做

            try{

                if(conn!=null) conn.close();

            }catch(SQLException se){

                se.printStackTrace();

            }

        }

        System.out.println("再见!");

    }

}