SpringBoot+Mybatis-Plus-增删改查整合案例

构建项目

选WEB项目和sql驱动

添加MP依赖

   <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.0</version>
        </dependency>

数据库连接配置

server:
  port: 80
spring:
  druid:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/cs?serverTimezone=UTC
    username: root
    password: root
#    添加表前缀
mybatis-plus:
  global-config:
    db-config:
      table-prefix: tbl_
#      id自增
      id-type: auto

数据库结构

/*
 Navicat Premium Data Transfer
 
 Source Server         : 2020_1_16win
 Source Server Type    : MySQL
 Source Server Version : 50729
 Source Host           : localhost:3306
 Source Schema         : ssm_db
 
 Target Server Type    : MySQL
 Target Server Version : 50729
 File Encoding         : 65001
 
 Date: 09/01/2022 22:32:11
*/
 
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
 
-- ----------------------------
-- Table structure for tbl_book
-- ----------------------------
DROP TABLE IF EXISTS `tbl_book`;
CREATE TABLE `tbl_book`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `type` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `description` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 13 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
 
-- ----------------------------
-- Records of tbl_book
-- ----------------------------
INSERT INTO `tbl_book` VALUES (1, '计算机理论', 'Spring实战 第5版', 'Spring入门经典教程，深入理解Spring原理技术内幕');
INSERT INTO `tbl_book` VALUES (2, '计算机理论', 'Spring 5核心原理与30个类手写实战', '十年沉淀之作，手写Spring精华思想');
INSERT INTO `tbl_book` VALUES (3, '计算机理论', 'Spring 5设计模式', '全方位解析面向Web应用的轻量级框架，带你成为Spring MVC开发高手');
INSERT INTO `tbl_book` VALUES (4, '计算机理论', 'Spring MVC+MyBatis开发从入门到项目实战', '源码级剖析Spring框架，适合已掌握Java基础的读者');
INSERT INTO `tbl_book` VALUES (5, '计算机理论', '轻量级Java Web企业应用实战', '源码级剖析Spring框架，适合已掌握Java基础的读者');
INSERT INTO `tbl_book` VALUES (6, '计算机理论', 'Java核心技术卷I基础知识(原书第11版)', 'Core Java第11版，Jolt大奖获奖作品，针对Java SE9、10、11全面更新');
INSERT INTO `tbl_book` VALUES (7, '计算机理论', '深入理解Java虚拟机', '5个维度全面剖析JVM，大厂面试知识点全覆盖');
INSERT INTO `tbl_book` VALUES (8, '计算机理论', 'Java编程思想(第4版)', 'Java学习必读经典,殿堂级著作!赢得了全球程序员的广泛赞誉');
INSERT INTO `tbl_book` VALUES (9, '计算机理论', '零基础学Java(全彩版)', '零基础自学编程的入门图书，由浅入深，详解Java语言的编程思想和核心技术');
INSERT INTO `tbl_book` VALUES (10, '市场营销', '直播就该这么做:主播高效沟通实战指南', '成长为网红的秘密都在书中');
INSERT INTO `tbl_book` VALUES (11, '市场营销', '直播销讲实战—本通', '和秋叶—起学系列网络营销书籍');
INSERT INTO `tbl_book` VALUES (12, '市场营销', '直播带货:淘宝、天猫直播从新手到高手', '—本教你如何玩转直播的书，10堂课轻松实现带货月入3W+');
 
SET FOREIGN_KEY_CHECKS = 1;

新建实体类

package com.springboot.domain;

import com.sun.tracing.dtrace.ArgsAttributes;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@ToString
@AllArgsConstructor //有参构造
@NoArgsConstructor //无参构造
@Data
public class Book {
    private  int id;
    private String type;
    private String name;
    private String description;

}

dao 层

package com.springboot.dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.springboot.domain.Book;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface BookDao extends BaseMapper<Book> {

}

测试

package com.springboot;

import com.springboot.dao.BookDao;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class SsmpDemoApplicationTests {
    @Autowired
    BookDao bookDao;
    @Test
    void contextLoads() {
        System.out.println(bookDao.selectById(1));
    }

}

业务层开发

package com.springboot.service;

import com.springboot.domain.Book;

import java.util.List;

public interface BookService {
    Boolean save(Book book);
    Boolean update(Book book);
    Boolean delete(Integer id);
    Book getById(Integer id);
    List<Book>getAll();

}

业务层实现

package com.springboot.service.impl;

import com.springboot.dao.BookDao;
import com.springboot.domain.Book;
import com.springboot.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service //定义成业务层对应的bean
public class BookServicelmpl implements BookService {
//    数据层接口
    @Autowired
    private BookDao bookDao;
    @Override
    public Boolean save(Book book) {
        return bookDao.insert(book)>0;
    }

    @Override
    public Boolean update(Book book) {
        return bookDao.updateById(book)>0;
    }

    @Override
    public Boolean delete(Integer id) {
        return bookDao.deleteById(id) >0;
    }

    @Override
    public Book getById(Integer id) {
        return bookDao.selectById(id);
    }

    @Override
    public List<Book> getAll() {
        return bookDao.selectList(null);
    }
}

测试

package com.springboot;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.springboot.dao.BookDao;
import com.springboot.domain.Book;
import com.springboot.service.impl.BookServicelmpl;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import sun.dc.pr.PRError;

import javax.management.QueryEval;

@SpringBootTest
class SsmpDemoApplicationTests {
    @Autowired
    private BookServicelmpl bookServicelmpl;
    @Test
    void getById() {

        System.out.println(bookServicelmpl.getById(1));
    }
}

业务层使用MP快速开发

继承IService接口

package com.springboot.service;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.extension.service.IService;
import com.springboot.domain.Book;

public interface IBookService extends IService<Book> {

}

业务层实现

通过ServiceImpl就完成了所有方法的实现

package com.springboot.service.Impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.springboot.dao.BookDao;
import com.springboot.domain.Book;
import com.springboot.service.IBookService;
import org.springframework.stereotype.Service;

// ServiceImpl 要给实现类和模型类
@Service
public class IBookServiceImpl extends ServiceImpl<BookDao,Book> implements IBookService {

}

测试

package com.springboot;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.springboot.dao.BookDao;
import com.springboot.domain.Book;
import com.springboot.service.IBookService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import sun.dc.pr.PRError;

import javax.management.QueryEval;

@SpringBootTest
class SsmpDemoApplicationTests {
    @Autowired
    private IBookService iBookService;
    @Test
    void getById() {

        System.out.println(iBookService.getById(1));
    }
}

添加自定义业务

不可和接口现有的方法重复

package com.springboot.service;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.extension.service.IService;
import com.springboot.domain.Book;

public interface IBookService extends IService<Book> {
    boolean saveBook(Book book);
}

单独去写他的实现就可以了

package com.springboot.service.Impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.springboot.dao.BookDao;
import com.springboot.domain.Book;
import com.springboot.service.IBookService;
import org.springframework.stereotype.Service;

// ServiceImpl 要给实现类和模型类
@Service
public class IBookServiceImpl extends ServiceImpl<BookDao,Book> implements IBookService {
    private BookDao bookDao;
    @Override
    public boolean saveBook(Book book) {
        return bookDao.insert(book)>0;
    }
}

表现层

package com.springboot.controller;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.springboot.domain.Book;
import com.springboot.service.IBookService;
import org.omg.CORBA.PUBLIC_MEMBER;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/books")
public class BookController {
//    调用业务层
    @Autowired
    private IBookService iBookService;
    @GetMapping
    public List<Book>getAll(){
//        查询全部
        return iBookService.list();
    }

    @PutMapping
    public boolean update(@RequestBody Book book){
//        修改
        return iBookService.updateById(book);
    }
    @PostMapping
    public boolean save(@RequestBody Book book){
//        新增
        return iBookService.save(book);
    }
    @DeleteMapping("{id}")
    public boolean delete(@PathVariable Integer id){
//        删除单个
        return iBookService.removeById(id);
    }
//    http:localhost/book/2
    @GetMapping("{id}")
    public Book getByID(  Integer id){
//        查询单个
        return iBookService.getById(id);
    }
//    分页
    @GetMapping("{start}/{end}")
    public IPage<Book> getPage(@PathVariable Integer start,@PathVariable Integer end){
        IPage page = new Page(start,end);
        return iBookService.page(page);
    }
}

新增数据

查询指定id

修改数据


删除数据

分页