[大数据]jdbc连接数据库笔记

导入依赖

<dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
</dependencies>

连接数据库

?创建package

?写代码，其中的异常全抛出，实际应用时注意使用try-catch语句，避免异常发生

package com.kuang.test;

import java.sql.*;

public class TestJdbc {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        //配置信息
        String url = "jdbc:mysql://localhost:3306/jdbc?useUnicode=true&characterEncoding=utf-8";
        String username = "root";
        String password = "333";


        //1、加载驱动
        Class.forName("com.mysql.jdbc.Driver");
        //2、创建连接类，连接数据库，该类代表了数据库
        Connection conn = DriverManager.getConnection(url, username, password);
        //3、获取声明对象Statement
        Statement stat = conn.createStatement();
        //4、编写SQL语句
        String sql = "select * from jdbc.users";
        //５、执行SQL语句并返回结果集，获取的声明对象Statement可以向数据库发送SQL语句
        ResultSet rs = stat.executeQuery(sql);
        //5、遍历输出结果
        while (rs.next()){
            System.out.println("id = " + rs.getObject("id"));
            System.out.println("name = " + rs.getObject("name"));
            System.out.println("password = " + rs.getObject("password"));
            System.out.println("email = " + rs.getObject("email"));
            System.out.println("birthday = " + rs.getObject("birthday"));
        }
        //6、关闭连接，释放资源（一定要做），后开的先关闭
        rs.close();
        stat.close();
        conn.close();

    }
}

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