JDBC 11-26作业

2024 年 11 月 26 日

373 次浏览

4385字数

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();
	}
}

```

JDBC 11-26作业