jdbc

package jdbc;

import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.*;

public class JdbcFirstDemo {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        //1.加载驱动  固定写法
        Class.forName("com.mysql.cj.jdbc.Driver");
        // 2.连接 用户信息和 u r l
        //支持中文编码   设定中文字符集utf8  ssl使用安全的连接
        //useUnicode=true&characterEncoding=utf8&useSSL=true
        String url ="jdbc:mysql://localhost:3306/jdbcstudy?useUnicode = true&characterEncoding = utf-8&useSSL = true&serverTimezone = GMT";        
        String username ="root";
        String password ="root";
        // 3.连接成功，返回一个数据库对象 Connection代表数据库
        Connection connection = DriverManager.getConnection(url,username,password);
        // 4.执行sql的对象Statement       执行sql的对象
        Statement statement =  connection.createStatement();
        // 5.执行sql的对象去执行 sql  可能存在的结果 查看返回结果
        String sql = "SELECT * FROM users";
        ResultSet resultSet = statement.executeQuery(sql);//返回的结果集，封装了全部查询出来的结果
        
        while (resultSet.next()) {
            System.out.println("id=" + resultSet.getObject("id"));
            System.out.println("name=" + resultSet.getObject("name"));
            System.out.println("pwd=" + resultSet.getObject("password"));
            System.out.println("email" + resultSet.getObject("email"));
            System.out.println("birth=" + resultSet.getObject("birthday"));
            
        }
        //6.释放连接 从后往前 先开放的后关闭
        resultSet.close();
        statement.close();
        connection.close();
    }
}