删除方法

StuDAO

package com.xiaohu.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.xiaohu.entity.StuEntity;

public class StuDAO {
    
    private Connection conn = null;
    private void connDB () {
        String Driver = "com.mysql.cj.jdbc.Driver";
        String user = "root";
        String password = "123456";
        String url = "jdbc:mysql://localhost:3306/test";
        try {
            
            Class.forName(Driver);
            conn = DriverManager.getConnection(url, user, password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        if(conn==null) {
            System.out.println("Connection DB Fail!");
        }
    
    }
    public StuEntity getOne(int sid) {
        StuEntity stu = new StuEntity();
        connDB();
        String sql = "select * from stuinfo where sid=?";
        try {
            PreparedStatement pre = conn.prepareStatement(sql);
            pre.setInt(1, sid);
            ResultSet rs = pre.executeQuery();
            while(rs.next()) {
                String saddress = rs.getString("saddress");
                int sage = rs.getInt("sage");
                String sname = rs.getString("sname");
                String ssex = rs.getString("ssex");
                stu.setSaddress(saddress);
                stu.setSage(sage);
                stu.setSid(sid);
                stu.setSname(sname);
                stu.setSsex(ssex);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return stu;
    }

    public List<StuEntity> getAll(){
        List<StuEntity> slist = new ArrayList<StuEntity>();
        
        connDB();
        
        String sql = "select * from stuinfo";
        try {
            PreparedStatement pre = conn.prepareStatement(sql);
            ResultSet rs = pre.executeQuery();
            while(rs.next()) {
                int sid = rs.getInt("sid");
                String sname = rs.getString("sname");
                String ssex = rs.getString("ssex");
                int sage = rs.getInt("sage");
                String saddress = rs.getString("saddress");
                StuEntity stu = new StuEntity();
                
                stu.setSaddress(saddress);
                stu.setSage(sage);
                stu.setSid(sid);
                stu.setSname(sname);
                stu.setSsex(ssex);
                
                slist.add(stu);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return slist;
    }
    public void delStu(int sid) {
        connDB();
        String sql = "delete from stuinfo where sid=?";
        try {
            PreparedStatement pre = conn.prepareStatement(sql);
            pre.setInt(1, sid);
            pre.execute();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

StuEntity

package com.xiaohu.entity;

public class StuEntity {
    private int sid;
    private String sname;
    private String ssex;
    private int sage;
    private String saddress;
    public int getSid() {
        return sid;
    }
    public void setSid(int sid) {
        this.sid = sid;
    }
    public String getSname() {
        return sname;
    }
    public void setSname(String sname) {
        this.sname = sname;
    }
    public String getSsex() {
        return ssex;
    }
    public void setSsex(String ssex) {
        this.ssex = ssex;
    }
    public int getSage() {
        return sage;
    }
    public void setSage(int sage) {
        this.sage = sage;
    }
    public String getSaddress() {
        return saddress;
    }
    public void setSaddress(String saddress) {
        this.saddress = saddress;
    }
    @Override
    public String toString() {
        return "StuEntity [sid=" + sid + ", sname=" + sname + ", ssex=" + ssex + ", sage=" + sage + ", saddress="
                + saddress + "]";
    }
    
}

Test

package com.xiaohu.test;

import java.util.List;
import java.util.Scanner;

import com.xiaohu.dao.StuDAO;
import com.xiaohu.entity.StuEntity;

public class Test1 {
    public static void main(String[] args) {
        StuDAO dao = new StuDAO();
        List<StuEntity> slist = dao.getAll();
        System.out.println("学号\t姓名\t性别\t年龄\t地址");
        for(StuEntity stu: slist) {
            System.out.println(stu.getSid()+"\t"+stu.getSname()+"\t"+stu.getSsex()+"\t"+stu.getSage()+"\t"+stu.getSaddress());
        }
        System.out.println("请输入需要删除的学生的sid");
        Scanner sc = new Scanner(System.in);
        int sid = sc.nextInt();
        StuEntity sstu = dao.getOne(sid);
        System.out.println(sstu.getSid()+"\t"+sstu.getSname()+"\t"+sstu.getSsex()+"\t"+sstu.getSage()+"\t"+sstu.getSaddress());
        System.out.println("确认删除请输入 Y,否则输入任意键退出");
        String comm = sc.next();
        if(comm.equals("Y") || comm.equals("y")) {
            dao.delStu(sid);
            System.out.println("删除成功");
        }else {
            System.out.println("取消删除");
        }
        sc.close();
    }
}