SSM：增删改查代码

 表示层（Controller）：StudentController

package com.ning.controller;

import com.ning.domain.Student;
import com.ning.service.StudentService;
import com.ning.vo.ResultInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
public class StudentController {

    @Autowired
    private StudentService studentService;

    //查询所有
    @GetMapping("/student")
    public ResultInfo findAll(){
        List<Student> studentList = studentService.findAll();
        return ResultInfo.success(studentList);
    }

    //新增
    @PostMapping("/student")
    public ResultInfo save(@RequestBody Student student){
        //调用service的save方法
        studentService.save(student);
        //返回结果
        return ResultInfo.success(null);
    }

    //根据number查询
    @GetMapping("/student/{number}")
    public ResultInfo findByNumber(@PathVariable("number") String number){
        //调用service的save方法
        Student student1 = studentService.findByNumber(number);
        //返回结果
        return ResultInfo.success(student1);
    }

    //根据number修改
    @PutMapping ("/student")
    public ResultInfo update(@RequestBody Student student){
        //调用service的save方法
        studentService.update(student);
        //返回结果
        return ResultInfo.success(null);
    }

    //根据number删除
    @DeleteMapping("/student/{number}")
    public ResultInfo delete(@PathVariable("number") String number){
        //调用service的save方法
        studentService.delete(number);
        //返回结果
        return ResultInfo.success(null);
    }
}

业务层（Service）接口：StudentService

package com.ning.service;

import com.ning.domain.Student;

import java.util.List;

public interface StudentService {

    //查询全部
    List<Student> findAll();

    //新增
    void save(Student student);

    //根据number查询
    Student findByNumber(String number);

    //根据number修改
    void update(Student student);

    //根据number删除
    void delete(String number);
}

业务层实现类：StudentServiceImpl

package com.ning.service.impl;

import com.ning.domain.Student;
import com.ning.mapper.StudentMapper;
import com.ning.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentServiceImpl implements StudentService {

    @Autowired
    private StudentMapper studentMapper;

    //查询全部
    @Override
    public List<Student> findAll() {
        //调用mapper（持久层）的findAll方法，操作数据库
        return studentMapper.findAll();
    }

    //新增
    @Override
    public void save(Student student) {
        //调用mapper（持久层）的save方法，操作数据库
        studentMapper.save(student);
    }

    //根据number查询
    @Override
    public Student findByNumber(String number) {
        //调用mapper（持久层）的findByNumber方法，操作数据库
        return studentMapper.findByNumber(number);
    }

    //根据number修改
    @Override
    public void update(Student student) {
        //调用mapper（持久层）的update方法，操作数据库
        studentMapper.update(student);
    }

    //根据number删除
    @Override
    public void delete(String number) {
        //调用mapper（持久层）的update方法，操作数据库
        studentMapper.delete(number);
    }
}

持久层（dao）接口：StudentMapper

package com.ning.mapper;

import com.ning.domain.Student;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import java.util.List;

public interface StudentMapper {

    //查询所有
    @Select("select * from student ")
    List<Student> findAll();

    //新增
    @Insert("insert into student values(#{number},#{name},#{birthday},#{address})")
    void save(Student student);

    //根据number查询
    @Select("select * from student where number = #{number}")
    Student findByNumber(String number);

    //根据number修改
    @Update("update student set name = #{name},birthday = #{birthday},address = #{address} where number = #{number}")
    void update(Student student);

    //根据number删除
    @Delete("delete from student where number = #{number}")
    void delete(String number);
}