一、导包

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>3.0.3</version>
</dependency>

二、配置数据库和MyBatis相关信息

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql:///book?serverTimezone=Asia/Shanghai
    username: root
    password: root

mybatis:
  type-aliases-package: com.boot.entity
  mapper-locations: /mapper/*.xml

三、建库建表插入数据

/*
 Navicat Premium Data Transfer

 Source Server         : locahost
 Source Server Type    : MySQL
 Source Server Version : 80036
 Source Host           : localhost:3306
 Source Schema         : book

 Target Server Type    : MySQL
 Target Server Version : 80036
 File Encoding         : 65001

 Date: 27/04/2024 20:51:04
*/

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for book
-- ----------------------------
DROP TABLE IF EXISTS `book`;
CREATE TABLE `book`  (
  `id` int NOT NULL AUTO_INCREMENT,
  `name` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  `type` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  `description` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 15 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of book
-- ----------------------------
INSERT INTO `book` VALUES (1, '三体', '科幻', '大刘的巅峰之作，将中国科幻推向世界舞台。总共分为三部曲：《地球往事》、《黑暗森林》、《死神永生》。');
INSERT INTO `book` VALUES (2, '格林童话', '童话', '睡前故事。');
INSERT INTO `book` VALUES (3, 'Spring 5设计模式', '计算机理论', '深入Spring源码剖析Spring源码中蕴含的10大设计模式');
INSERT INTO `book` VALUES (4, 'Spring MVC+ MyBatis开发从入门到项目实战', '计算机理论', '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 `book` VALUES (5, '轻量级Java Web企业应用实战', '计算机理论', '源码级剖析Spring框架,适合已掌握Java基础的读者');
INSERT INTO `book` VALUES (6, 'Java核心技术卷|基础知识(原书第11版)', '计算机理论', 'Core Java第11版，Jolt大奖获奖作品，针对Java SE9、10、 11全面更新');
INSERT INTO `book` VALUES (7, '深入理解Java虚拟机', '计算机理论', '5个维度全面剖析JVM,面试知识点全覆盖');
INSERT INTO `book` VALUES (8, 'Java编程思想(第4版)', '计算机理论', '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 `book` VALUES (9, '零基础学Java (全彩版)', '计算机理论', '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 `book` VALUES (10, '直播就该这么做:主播高效沟通实战指南', '市场营销', '李子柒、李佳琦、薇娅成长为网红的秘密都在书中');
INSERT INTO `book` VALUES (11, '直播销讲实战一本通', '市场营销', '和秋叶一起学系列网络营销书籍');
INSERT INTO `book` VALUES (12, '直播带货:淘宝、天猫直播从新手到高手', '市场营销', '一本教你如何玩转直播的书， 10堂课轻松实现带货月入3W+');
INSERT INTO `book` VALUES (13, 'Spring实战第5版', '计算机理论', 'Spring入门经典教程,深入理解Spring原理技术内幕');
INSERT INTO `book` VALUES (14, 'Spring 5核心原理与30个类手写实战', '计算机理论', '十年沉淀之作，写Spring精华思想');

SET FOREIGN_KEY_CHECKS = 1;

四、编写对应的实体类

@Data
public class Book {

    private Integer id;
    private String name;
    private String type;
    private String description;

}

五、编写Mapper接口和对应的XML映射文件

@Mapper
public interface BookMapper {

    List<Book> findAll();

}

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

<mapper namespace="com.boot.mapper.BookMapper">
    <select id="findAll" resultType="Book">
        select * from book
    </select>
</mapper>

六、在Service层调用Mapper接口查询

@Service
public class BookServiceImpl implements BookService {

    @Autowired
    private BookMapper bookMapper;

    @Override
    public List<Book> findAll() {
        return bookMapper.findAll();
    }
}