Spring boot的增删改查

数据库
使用的是MySQL数据库
数据库的写的字段有些多所以有些代码比较繁杂

目录结构

application.yml
1901java为数据库

spring:
  thymeleaf:
    cache: false
  datasource:
    username: root
    password: root
    #    数据库地址和 编码 数据加密 设置时区
    url: jdbc:mysql://localhost:3306/1901java?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=GMT%2B8
    #serverTimezone=UTC
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
server:
  port: 8080
  servlet:
    context-path:

Entity–》Student

package com.yyy.demo.Entity;


import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import java.util.Date;

@Table
@Entity(name = "student")
public class Student {
    @Id
    private int sid;
    private String sname;
    private int sex;
    private String  scard;
    private String  stelephone;
    private Date sbirthday;
    private int cid;
    //此处省略set，get方法

Dao–》StudentDao
继承的JpaRepository 接口自带
（使用了里面的findAll和save方法）
（修改的方法其实也可以直接调用save添加方法）

package com.yyy.demo.Dao;

import com.yyy.demo.Entity.Student;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component;

import javax.transaction.Transactional;
import java.util.Date;
import java.util.Map;

@Component
public interface StudentDao extends JpaRepository<Student,Integer> {
    //删除
    @Transactional
    @Modifying
    @Query(name="deleteBySid",value="delete from student where sid= :sid",nativeQuery=true)
    void deleteBySid(@Param("sid") Integer sid);
    //按照id查询
    @Query(name="findBySid",value="select * from student where sid = :sid",nativeQuery=true)
    Map findBySid(@Param("sid") Integer sid);
    //修改
    @Transactional
    @Modifying
    @Query(name="update",
            value="update student set sname=?1 ,sex=?2,scard=?3,stelephone=?4,sbirthday=?5,cid=?6 where sid=?7",
            nativeQuery=true)
    void update(String name, int sex, String scard, String stelephone, Date sbirthday,int cid,int sid);
}

Service–》StudentService

package com.yyy.demo.Service;

import com.yyy.demo.Dao.StudentDao;
import com.yyy.demo.Entity.Student;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Date;
import java.util.List;
import java.util.Map;

@Service
public class StudentService {

    @Resource
    StudentDao studentDao;
    //查询全部
    public List<Student> findAll(){
        return studentDao.findAll();
    }
    //添加
    public Student addAll(Student student){
        return studentDao.save(student);
    }
    //删除
    public void deleteBySid(int sid){
        studentDao.deleteBySid(sid);
    }
    //根据sid查询
    public Map findBySid(int sid){
        return studentDao.findBySid(sid);
    }
    //修改
    public void update(String name, int sex, String scard, String stelephone, Date sbirthday, int cid, int sid){
        studentDao.update(name,sex,scard,stelephone,sbirthday,cid,sid);
    }
}

Controller–》StudentController

package com.yyy.demo.Controller;


import com.yyy.demo.Entity.Student;
import com.yyy.demo.Service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.List;
import java.util.Map;

@Controller
@RequestMapping("/toStudent")
public class StudentController {
    @Autowired
    StudentService studentService;
    //查询
    @RequestMapping("/findAll")
    public String findAll(Model model){
        List<Student> list = studentService.findAll();
        model.addAttribute("student",list);
        return "Student";
    }
    //跳转添加页面
    @RequestMapping("/toadd")
    public String toadd(){
        return "add";
    }
    //获取添加页面内容，带哦用添加方法，添加
    @RequestMapping("/addAll")
    public String addAll(HttpServletRequest request) throws ParseException {
        int sid = Integer.parseInt(request.getParameter("sid"));
        String sname = request.getParameter("sname");
        int sex = Integer.parseInt(request.getParameter("sex"));
        String scard = request.getParameter("scard");
        String stelephone = request.getParameter("stelephone");
        java.util.Date date = new SimpleDateFormat("yyyy-MM-dd").parse(request.getParameter("sbirthday"));
        int cid = Integer.parseInt(request.getParameter("cid"));
        Student student = new Student();
        student.setSid(sid);
        student.setSname(sname);
        student.setSex(sex);
        student.setScard(scard);
        student.setStelephone(stelephone);
        student.setSbirthday(date);
        student.setCid(cid);
        studentService.addAll(student);
        return "redirect:/toStudent/findAll";
    }
    //获取页面的sid，调用删除方法
    @RequestMapping("/deleteBySid")
    public String deleteBySid(HttpServletRequest request){
        int sid = Integer.parseInt(request.getParameter("sid"));
        studentService.deleteBySid(sid);
        return "redirect:/toStudent/findAll";
    }
    //跳转到修改页面
    @RequestMapping("/toupload")
    public String toupload(HttpServletRequest request,Model model){
        int sid = Integer.parseInt(request.getParameter("sid"));
        Map map = studentService.findBySid(sid);
        model.addAttribute("student",map);
        return "upload";
    }
    //修改--可以不写，用添加方法代替
    @RequestMapping("/doupdate")
    public String doupdate(HttpServletRequest request) throws ParseException {
        int sid = Integer.parseInt(request.getParameter("sid"));
        String sname = request.getParameter("sname");
        int sex = Integer.parseInt(request.getParameter("sex"));
        String scard = request.getParameter("scard");
        String stelephone = request.getParameter("stelephone");
        java.util.Date date = new SimpleDateFormat("yyyy-MM-dd").parse(request.getParameter("sbirthday"));
        int cid = Integer.parseInt(request.getParameter("cid"));
        Student student = new Student();
        student.setSid(sid);
        student.setSname(sname);
        student.setSex(sex);
        student.setScard(scard);
        student.setStelephone(stelephone);
        student.setSbirthday(date);
        student.setCid(cid);
        studentService.update(sname,sex,scard,stelephone,date,cid,sid);
        return "redirect:/toStudent/findAll";
    }
}

HTML页面
Student.html
查询显示页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<center>
    <table border="1" width="80%">
        <tr>
            <th colspan="9"><h1>学生信息展示</h1></th>
        </tr>
        <tr>
            <th colspan="9"><a href="/toStudent/toadd">添加</a></th>
        </tr>
        <tr>
            <td>编号</td>
            <td>姓名</td>
            <td>性别</td>
            <td>身份证</td>
            <td>手机号</td>
            <td>生日</td>
            <td>班级</td>
            <td>操作</td>
        </tr>
        <tr th:each = "student:${student}">
            <td th:text="${student.sid}"></td>
            <td th:text="${student.sname}"></td>
            <td th:text="${student.sex}"></td>
            <td th:text="${student.scard}"></td>
            <td th:text="${student.stelephone}"></td>
            <td th:text="${student.sbirthday}"></td>
            <td th:text="${student.cid}"></td>
            <td>
                <a th:href="@{/toStudent/deleteBySid(sid=${student.sid})}">删除</a>
                <a th:href="@{/toStudent/toupload(sid=${student.sid})}">修改</a>
            </td>
        </tr>
    </table>
</center>
</body>
</html>

add.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<center>
    <h1>添加学生信息</h1>
    <table border="1">
        <form action="/toStudent/addAll" method="post">
            <tr>
                <td>编号：</td>
                <td><input type="text" name="sid"/></td>
            </tr>
            <tr>
                <td>姓名：</td>
                <td><input type="text" name="sname"/></td>
            </tr>
            <tr>
                <td>性别：</td>
                <td><input type="text" name="sex"/></td>
            </tr>
            <tr>
                <td>身份证：</td>
                <td><input type="text" name="scard"/></td>
            </tr>
            <tr>
                <td>手机号：</td>
                <td><input type="text" name="stelephone"/></td>
            </tr>
            <tr>
                <td>生日：</td>
                <td><input type="date" name="sbirthday"/></td>
            </tr>
            <tr>
                <td>cid：</td>
                <td><input type="text" name="cid"></td>
            </tr>
            <tr>
                <td colspan="2">
                    <input type="submit" value="添加">
                    <input type="reset" value="取消">
                </td>
            </tr>
        </form>
    </table>
</center>
</body>
</html>

upload.html
调用根据sid查询的方法，获取原先的值

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<center>
    <h1>修改学生信息</h1>
    <table border="1">
        <form action="/toStudent/doupdate" method="post">
            <tr>
                <td>编号：</td>
                <td><input type="text"  th:value="${student.sid}" readonly name="sid" /><font color="red">慢慢改</font></td>
            </tr>
            <tr>
                <td>姓名：</td>
                <td><input type="text" th:value="${student.sname}" name="sname"/></td>
            </tr>
            <tr>
                <td>性别：</td>
                <td><input type="text" th:value="${student.sex}" name="sex"/></td>
            </tr>
            <tr>
                <td>身份证：</td>
                <td><input type="text" th:value="${student.scard}" name="scard"/></td>
            </tr>
            <tr>
                <td>手机号：</td>
                <td><input type="text" th:value="${student.stelephone}" name="stelephone"/></td>
            </tr>
            <tr>
                <td>生日：</td>
                <td><input type="date" th:value="${student.sbirthday}" name="sbirthday"/></td>
            </tr>
            <tr>
                <td>cid：</td>
                <td><input type="text" th:value="${student.cid}"  name="cid"></td>
            </tr>
            <tr>
                <td colspan="2">
                    <input type="submit" value="修改">
                    <input type="reset" value="取消">
                </td>
            </tr>
        </form>
    </table>
</center>
</body>
</html>

世界上什么都有，就是没有如果。