mybatis前传-回顾使用JDBC连接数据库

create database if not EXISTS `practice`;
use practice;
create table if not EXISTS student(
		id int(11) not null auto_increment primary key COMMENT '学号',
		sname VARCHAr(50) COMMENT '姓名',
		sage int(11) COMMENT '年龄',
		ssex VARCHAr(2) COMMENT '性别'

)ENGINE=INNODB DEFAULT charset=utf8;

insert into student(sname,sage,ssex) VALUES('张三',18,'男'),('李四',17,'女'),('王五',18,'女');

package com.yh.pojo;

public class Student {
    private int id;
    private String sname;
    private int sage;
    private String ssex;

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", sname='" + sname + ''' +
                ", sage=" + sage +
                ", ssex='" + ssex + ''' +
                '}';
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getSname() {
        return sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }

    public int getSage() {
        return sage;
    }

    public void setSage(int sage) {
        this.sage = sage;
    }

    public String getSsex() {
        return ssex;
    }

    public void setSsex(String ssex) {
        this.ssex = ssex;
    }
}

package com.yh.utils;

import org.junit.Test;

import java.sql.*;

public class Test{
    @Test
    public void test01() throws ClassNotFoundException {
        //获取驱动
        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost:3306/practice?useUnicode=true&characterEncoding=utf-8";
        String username = "root";
        String password = "root";
        //获取数据库连接
        Connection connection = null;
        try {
        
            connection = DriverManager.getConnection(url, username, password);
		//获取PreparedStatement 对象
            PreparedStatement statement = connection.prepareStatement("select * from student");
		//执行sql，获取结果集
            ResultSet resultSet = statement.executeQuery();
            //遍历结果集，获取查询结果
            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String sname = resultSet.getString("sname");
                int sage = resultSet.getInt("sage");
                String ssex = resultSet.getString("ssex");
                System.out.println(id+"-"+sname+"-"+sage+"-"+ssex);
            }
            //应该将这部分放在finally中释放资源
            resultSet.close();
            statement.close();
            connection.close();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
    }
}