Spring Boot 知识笔记（整合Mybatis续-补充增删改查）

续上篇，补充数据库增删改查的其他场景。

一、Mapper中添加其他场景操作

package net.Eleven.demo.Mapper;

import net.Eleven.demo.domain.UserNew;
import org.apache.ibatis.annotations.*;

import java.util.List;

/**
 * 功能描述：访问数据库的接口，相当于dao层
 * @author Eleven
 */

public interface UserMapper {

    //推荐使用#{}取值，不要用${},因为存在注入的风险

    /**
     * 向数据库插入一条数据
     * @param userNew
     * @return
     */
    @Insert("INSERT INTO user(name,phone,create_time,age) VALUES(#{name},#{phone},#{creatTime},#{age})")
    @Options(useGeneratedKeys = true,keyProperty = "id",keyColumn = "id") //keyProperty java对象的属性；keyColumn表示数据库的字段
    int insert(UserNew userNew);

    /**
     * 查找全部，功能比较简单，也可以直接跳过service层，直接在controller注入mapper
     * @return
     */
    @Select("select * from user")
    @Results({@Result(column = "create-time",property = "createTime")})
    List<UserNew> getAllUser();

    /**
     * 根据id查询，返回的是一个user对象
     * @param id
     * @return
     */
    @Select("select * from user where id=#{id}")
    @Results({@Result(column = "create-time",property = "createTime")})
    UserNew  findById(int id);

    /**
     * 根据id更新对象的name
     * @param userNew
     */
    @Update("update user set name=#{name} where id=#{id}")
    void updateById(UserNew userNew);

    /**
     * 根据id，删除一个对象
     */
    @Delete("delete from user where id =#{id}")
    void deleteById(int id);

}

二、impl文件中增加对应的调用mapper的方法

package net.Eleven.demo.Service.impl;

import net.Eleven.demo.Mapper.UserMapper;
import net.Eleven.demo.Service.UserService;
import net.Eleven.demo.domain.UserNew;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.validation.constraints.Null;
import java.util.List;

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;

    @Override
    public int add(UserNew userNew) {
        userMapper.insert(userNew);
        int id = userNew.getId();
        return id;
    }

    //查找所有，对应mapper的getAlluser
    public Object findAll(){
        return userMapper.getAllUser();
    }

    //根据id查找，对应mapper的findById
    public Object findById(int id){
        return userMapper.findById(id);
    }

    //更新一个对象
    public void updateById(UserNew userNew){
         userMapper.updateById(userNew);
    }

    //删除一个对象
    public  void deleteById(int id){
        userMapper.deleteById(id);
    }
}

三、controller中增加对应的request请求，通过注入，调用impl的方法，继而执行数据库命令。

package net.Eleven.demo.controller;

import net.Eleven.demo.Service.UserService;
import net.Eleven.demo.Service.impl.UserServiceImpl;
import net.Eleven.demo.domain.JsonData;
import net.Eleven.demo.domain.UserNew;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Date;

@RestController
@RequestMapping("/api/sql/user")
public class UserController {
    @Autowired
    private UserService userService;
    @Autowired
    private UserServiceImpl userServiceImpl;
    @GetMapping("add")
    public Object userAdd(){
        UserNew userNew = new UserNew();
        userNew.setAge(11);
        userNew.setCreatTime(new Date());
        userNew.setName("Eleven");
        userNew.setPhone("18211111111");
        int id = userService.add(userNew);
        return JsonData.buildSuccess(id);
    }

    //查找全部
    @GetMapping("find_all")
    public Object findAll(){
        return JsonData.buildSuccess(userServiceImpl.findAll());
    }

    //根据id查找对象
    @GetMapping("find_by_id")
    public Object findById(int id){
        return JsonData.buildSuccess(userServiceImpl.findById(id));
    }

    //根据id更新对象的name
    @GetMapping("update_by_id")
    public Object updateById(String name,int id){
         UserNew userNew = new UserNew();
        userNew.setName(name);
        userNew.setId(id);
        userServiceImpl.updateById(userNew);
        return JsonData.buildSuccess();
    }

    //根据id删除对象
    @GetMapping("delete_by_id")
    public  Object deleteById(int id){
        userServiceImpl.deleteById(id);

    }

}

四、执行结果