JDBC

1.下载jar包

1. 下载地址：mvnrepository

2. 搜索jar包
   

3. 下载对应的版本

2.导入包

项目的根目录下新建lib目录，将下载好的包复制进去，最后右击lib目录->Add as Library...

3.编写代码

package com.sanduo.lesson01;


import java.sql.*;

// 第一个jdbc程序
public class JdbcFirstDemo {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        //1. 加载驱动
        Class.forName("com.mysql.jdbc.Driver"); //反射实现
        //2. 用户信息url
        // useUnicode=true&characterEncoding=utf8&useSSL=true
        String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=true";
        String username = "root";
        String password = "root";
        //3. 连接成功，数据库对象 Connection 代表数据库
        Connection connection = DriverManager.getConnection(url, username, password);
        //4. 执行SQL的对象 Statement 执行SQL
        Statement statement = connection.createStatement();
        //5. 执行SQL的对象去执行SQL
        String sql = "select * from `user`";
        ResultSet resultSet = statement.executeQuery(sql);// 回返的结果集
        if(!resultSet.next()){
            System.out.println("暂无数据");
        }
        while (resultSet.next()){
            System.out.println("id="+resultSet.getObject("id"));
            System.out.println("name="+resultSet.getObject("name"));
            System.out.println("age="+resultSet.getObject("age"));
            System.out.println("password="+resultSet.getObject("password"));
        }

        //6. 释放连接
        resultSet.close();
        statement.close();
        connection.close();

    }
}

4.分析代码