spring boot CRUD(查询全部，查询ID,模糊查询，删除id，全部删除，新增多条/单条 修改)

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example.DemoCrud</groupId>
    <artifactId>democurd</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>democurd</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- mybatis整合Springboot -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>

        <dependency>
            <!--           maven 添加json-->
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
        </dependency>
        <!--jquery-webjar-->
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>3.3.0</version>
        </dependency>
        <!--bootstrap-webjar-->
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>bootstrap</artifactId>
            <version>4.0.0</version>
        </dependency>
        <!--配置文件注入时使用后会有提示-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.18</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

/*
 Navicat Premium Data Transfer

 Source Server         : deptuser
 Source Server Type    : MySQL
 Source Server Version : 80020
 Source Host           : localhost:3306
 Source Schema         : cruddemo

 Target Server Type    : MySQL
 Target Server Version : 80020
 File Encoding         : 65001

 Date: 08/07/2022 23:11:12
*/

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` int(0) NOT NULL,
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NULL DEFAULT NULL,
  `age` int(0) NULL DEFAULT NULL,
  `password` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NULL DEFAULT NULL,
  `newdate` datetime(0) NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_bin ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (11, '44', 77, '44', '2022-07-08 01:55:42');
INSERT INTO `user` VALUES (16, '88', 88, '8888', '2022-07-08 00:00:00');
INSERT INTO `user` VALUES (18, '44', 77, '44', '2022-07-08 02:12:43');
INSERT INTO `user` VALUES (21, '44', 77, '44', '2022-07-08 02:15:14');
INSERT INTO `user` VALUES (22, '44', 77, '44', '2022-07-08 02:15:14');
INSERT INTO `user` VALUES (23, '44', 77, '44', '2022-07-08 02:15:14');
INSERT INTO `user` VALUES (24, '44', 77, '44', '2022-07-08 02:15:14');
INSERT INTO `user` VALUES (36, 'tt', 44, '12345456', '2022-07-03 00:08:25');

SET FOREIGN_KEY_CHECKS = 1;

# thymeleaf
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.check-template-location=true
spring.thymeleaf.suffix=.html
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.servlet.content-type=text/html
spring.thymeleaf.mode=HTML5
spring.thymeleaf.cache=false

spring:
  datasource:
    name:
    url: jdbc:mysql://127.0.0.1:3306/cruddemo?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=UTC
    username: root
    password: root
  messages:
    ##message.propertiesi是默认的国际化配置文件，不需要特别指定路径
    basename: i18n.login

  ##禁用thymeleaf的缓存
  thymeleaf:
    cache: false

mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.example.democru.pojo

server:
  port: 6688
  servlet:
    context-path: /

package com.example.democrud.democurd;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

@SpringBootApplication(scanBasePackages = "com.example") //指定项目扫描不加也可以
@MapperScan(basePackages = "com.example.democrud.democurd.usermapper") //mapper 经常不自动加载故加了下
//@SpringBootApplication(exclude = DataSourceAutoConfiguration.class) //排除掉数据库自动加载
public class DemocurdApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemocurdApplication.class, args);
    }

}

package com.example.democrud.democurd.controller;


import com.example.democrud.democurd.pojo.userdemo;
import com.example.democrud.democurd.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

//@RestController
@Controller
@RequestMapping("/user/")
public class CrudController {

    @Autowired
    public UserService userService;

    @RequestMapping("abc")
    @ResponseBody
    public String hello() {
        return "hello  你好";
    }

    /**
     * 查询  ：模糊查询 单点查询  查询全部
     * 删除
     * 增加 数据
     * <p>
     *
     *
     * @param
     */
//    public static void main(String[] args) {
//
//    }

    /**
     * 查询全部
     *http://localhost:6688/user/findall
     * @return
     */
    @ResponseBody
    @GetMapping("findall")
    public List<userdemo> findAll() {
        System.out.println("执行controller");
        List<userdemo> findall = userService.findall();
        System.out.println(findall);
        return findall;
    }

    /**
     * 查询id
     *http://localhost:6688/user/find/id
     * @param id
     * @return
     */
    @ResponseBody
    @GetMapping("findid/{id}")
    public List<userdemo> findId(@PathVariable(value = "id") int id) {

        System.out.println("id" + id);
        List<userdemo> le = userService.findid(id);
        return le;
    }

    /**
     * http://localhost:6688/user/find/{like=》模糊查询的数据}
     * 模糊查询 相关数据
     * @param like
     * @return
     */
    @ResponseBody
    @GetMapping("find/{like}")
    public List<userdemo> findLike(@PathVariable String like) {
        System.out.println("like" + like);
        List<userdemo> likes = userService.findlike(like);
        return likes;
    }

    /**
     * http://localhost:6688/user/delectall
     * 删除全部
     * @return
     */
    @ResponseBody
    @GetMapping("delectall")
    public String delectAll() {
        System.out.println("删除全部");
        int delect = userService.delectAll();
        // 返回删除的条数 String.valueOf(delect)
        if (delect > 0) {
            String le = "删除成功,删除了" + delect + "条数据";
            return le;
        } else {

            return "删除失败,或者无可删除数据";
        }
    }

    /**
     * http://localhost:6688/user/delect/id(写删除的id)
     * 根据id删除
     * @param id
     * @return
     */
    @ResponseBody
    @GetMapping("delect/{id}")
    public String delectId(@PathVariable int id) {
        int le = userService.delectId(id);
        if (le > 0) {
            String lee = "删除成功删除了一条数据 id为" + id;
            return lee;
        } else {
            return "删除失败";
        }

    }

    /**
     * http://localhost:6688/user/delectBatches
     * 刪除多個 傳入多個id即可
     * @return
     */
    @ResponseBody
    @GetMapping("delectBatches")
    public String delectBatches() {
        int le = 0;
        int[] nee = {34, 35};
        for (int i = 0; i < nee.length; i++) {
            le = userService.delectId(nee[i]);
        }
        if (le > 0) {
            String lee = "删除成功";
            return lee;
        } else {
            return "删除失败";
        }
    }

    /**
     * http://localhost:6688/user/addOnce
     *新增一个 或者批量新增
     * @param userdemo
     * @return
     */
    @ResponseBody
    @GetMapping("addOnce") // 一般采用put 请求但是这个demo不涉及前后交互
    public int addOnce(userdemo userdemo) {
        List<userdemo> userdemos = new ArrayList<>();
        Date lee = new Date();
        //新增一个或者多个
        userdemos.add(new userdemo("21", "44", "77", "44", lee));
        userdemos.add(new userdemo("22", "44", "77", "44", lee));
        userdemos.add(new userdemo("23", "44", "77", "44", lee));
        userdemos.add(new userdemo("24", "44", "77", "44", lee));

        int lo = userService.addOnce(userdemos);

        if (lo > 0) {
            System.out.println("您新增了" + lo + "条数据");
        } else {
            System.out.println("无新增");
        }

        return lo;
    }

    /**
     * http://localhost:6688/user/update  修改
     * @param userdemo
     * @return
     */
    @ResponseBody
    @GetMapping("update")
    public int update(userdemo userdemo) {
  //后端直接伪数据  进行赋值  发送新的数据
        userdemo.setId("16");
        userdemo.setName("88");
        userdemo.setAge("88");
        userdemo.setPassword("8888");
        userdemo.setNewdate(new Date());

        System.out.println(userdemo.toString());
         int le=userService.updateid(userdemo);

         if (le>0){
             System.out.println("修改完成");
         }

         return le;

    }


}

package com.example.democrud.democurd.pojo;


import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.Date;

@Data  //get/set方法
@AllArgsConstructor  //有参构造
@NoArgsConstructor   //无参构造
public class userdemo {


    private String id;
    private String name;
    private String age;
    private String password;
    private Date newdate;



}

package com.example.democrud.democurd.service;

import com.example.democrud.democurd.pojo.userdemo;

import java.util.List;

public interface UserService {
      List<userdemo> findall();

      List<userdemo> findid(int id);

      List<userdemo> findlike(String like);

      int delectAll();

      int delectId(int id);

      int addOnce(List<userdemo> userdemos);

      int updateid(userdemo userdemo);
}

package com.example.democrud.democurd.service;

import com.example.democrud.democurd.pojo.userdemo;
import com.example.democrud.democurd.usermapper.DaoMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

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

@Service
public class UserServiceImpl implements UserService {

    //@Autowired   使用aut ...装备坏报错故推荐这个
   // @Autowired
    @Resource
    private DaoMapper daoMappers;


    /**
     * @Autowired是一种注解，可以对成员变量、方法和构造函数进行标注，来完成自动装配的工作，
     * @Autowired标注可以放在成员变量上，也可以放在成员变量的set方法上，也可以放在任意方法上表示，
     * 自动执行当前方法，如果方法有参数，会在IOC容器中自动寻找同类型参数为其传值。
     */

    /**
     * @Override这个标签有什么用呢。。。。。。
     * 其实我也是比较迷茫，查了一下，三个作用吧
     * 1. 可以给你当作注释用，感觉这个也不能说明什么，注释也没什么用。
     * 2. 可以告诉读你代码的人，这是对它父类方法的重写，其实很多代码规范没有为什么，规范就是规范，
     * 代码的可读性还是很重要的。
     * 3. 编译器可以给你验证@Override下面的方法名称是否是你父类中所有的，如果没有就会报错。
     *
     * 比如当你想要在子类中重写父类的一个方法，但是你把名字打错了，当你写了@Override编译器会提示你，
     * 你写的这个方法父类中没有；但是如果你没有写@Override编译器就会觉得这个是你子类中写的新的方法，
     * 并不会报错，到时候你debug还是很麻烦的一件事。
     *
     * @return
     */
    @Override
    public List<userdemo> findall() {
        return  daoMappers.findall();
    }

    @Override
    public List<userdemo> findid(int id) {
        return daoMappers.findid(id);
    }

    @Override
    public List<userdemo> findlike(String like) {
        return daoMappers.findlike(like);
    }

    @Override
    public int delectAll() {
        return daoMappers.delectAll();
    }

    @Override
    public int delectId(int id) {
        return daoMappers.delectId(id);
    }

    @Override
    public int addOnce(List<userdemo> userdemos) {
        return daoMappers.addOnce(userdemos);
    }

    @Override
    public int updateid(userdemo userdemo) {
        return daoMappers.updateid(userdemo);
    }


}

package com.example.democrud.democurd.usermapper;

import com.example.democrud.democurd.pojo.userdemo;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;


import java.util.List;

@Mapper
public interface DaoMapper {

  List<userdemo> findall();


  List<userdemo> findid(int id);

  List<userdemo> findlike(String like);

  int delectAll();

  int delectId(int id);

  int addOnce(List<userdemo> userdemos);

  int updateid(userdemo userdemo);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!--数据源文件（告知程序着是数据源从这里拿数据Repository）-->
<mapper namespace="com.example.democrud.democurd.usermapper.DaoMapper">

    <resultMap id="userMap" type="com.example.democrud.democurd.pojo.userdemo">
        <id column="id" property="id" jdbcType="INTEGER"/>
        <result column="name" property="name"/>
        <result column="age" property="age"/>
        <result column="password" property="password"/>
        <result column="newdate" property="newdate"/>
    </resultMap>

    <sql id="lee">
        id,name,age,password,newdate
    </sql>
    

    <select id="findall" parameterType="com.example.democrud.democurd.pojo.userdemo" resultMap="userMap">
        select
       <include refid="lee"/> from user
    </select>
<!--    parameterType 传入值的类型 决定-->
    <select id="findid" parameterType="integer"  resultMap="userMap">
        select <include refid="lee"></include>
       from user  where id=#{id}
    </select>
    <select id="findlike" resultType="com.example.democrud.democurd.pojo.userdemo"  parameterType="com.example.democrud.democurd.pojo.userdemo">
               select <include refid="lee"></include>
             from USER  WHERE id   LIKE CONCAT('%',#{LIKE},'%')
             OR name  LIKE CONCAT('%',#{LIKE},'%')  OR age LIKE  CONCAT('%',#{LIKE},'%')
    </select>



    <delete id="delectAll" parameterType="int">
     delete from user
    </delete>



    <delete id="delectId" parameterType="int">
        delete  from user  where id=#{id}
    </delete>


  <!--<insert id="addOnce" parameterType="com.example.democrud.democurd.pojo.userdemo">
      insert  into user
      <trim prefix="(" suffix=")" suffixOverrides="," >
          <if test="id != null" >
              id,
          </if>
          <if test="name != null" >
              name,
          </if>
          <if test="age != null" >
              age,
          </if>
          <if test="password != null" >
              password,
          </if>
          <if test="newdate != null" >
              newdate,
          </if>
      </trim>
      <trim prefix="values (" suffix=")" suffixOverrides="," >
          <if test="id != null" >
              #{id,jdbcType=VARCHAR},
          </if>
          <if test="name != null" >
              #{name,jdbcType=VARCHAR},
          </if>
          <if test="age != null" >
              #{age,,jdbcType=VARCHAR},
          </if>
          <if test="password != null" >
              #{password,jdbcType=VARCHAR},
          </if>
          <if test="newdate != null" >
              #{newdate,jdbcType=DATE},
          </if>
      </trim>
  </insert>-->


    <insert id="addOnce" parameterType="int">
        insert into user (id,name,age,password,newdate)
        values
        <foreach collection="list" item="item" separator=",">
            (
            #{item.id}, #{item.name},#{item.age},#{item.password},#{item.newdate}
            )
        </foreach>
    </insert>


<!--    <update id="updateid" parameterType="int">-->
    <!--         update user set-->
    <!--      name=#{name},age=#{age},password=#{password},newdate={newdate}-->
    <!--       where id=#{id}-->
    <!--    </update>-->


    <update id="updateid" parameterType="int">
    update  user
    <set>
        <if test="name !=null">
            name =#{name,jdbcType=VARCHAR},
        </if>
        <if test="age !=null">
            age=#{age,jdbcType=VARCHAR},
        </if>
        <if test="password !=null">
            password=#{password,jdbcType=VARCHAR},
        </if>
        <if test="newdate !=null">
            newdate=#{newdate,jdbcType=DATE},
        </if>
    </set>

    where id=#{id,jdbcType=VARCHAR}
</update>

</mapper>