MyBatis-Plus（基于springboot）直接上手javaNym车厘子-

数据库文件（mybatis_plus 数据库名字）

整体的工程结构

雪花算法，自动生成id传送门

DROP TABLE IF EXISTS user; CREATE TABLE user ( id BIGINT(20) NOT NULL COMMENT '主键ID', name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名', age INT(11) NULL DEFAULT NULL COMMENT '年龄', email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱', PRIMARY KEY (id) );INSERT INTO user (id, name, age, email) VALUES (1, 'Jone', 18, 'test1@baomidou.com'), (2, 'Jack', 20, 'test2@baomidou.com'), (3, 'Tom', 28, 'test3@baomidou.com'), (4, 'Sandy', 21, 'test4@baomidou.com'), (5, 'Billie', 24, 'test5@baomidou.com'); 

pom.xml文件 需要添加的

 <!-- 数据库驱动 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!-- lombok --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </dependency> <!-- mybatis-plus --> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.0.5</version> </dependency> 

1.这里UserMapper，不需要在配置繁琐的xml文件

package com.xyj.mapper; import com.baomidou.mybatisplus.core.mapper.BaseMapper; import com.xyj.pojo.User; import org.springframework.stereotype.Repository; /**  * @author xyj  * @date 2020/4/24 -10:20  */ @Repository public interface UserMapper extends BaseMapper<User>{ } 

2.pojo层里的User，与数据库对应

package com.xyj.pojo; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; /**  * @author xyj  * @date 2020/4/24 -10:17  */ @Data @AllArgsConstructor @NoArgsConstructor public class User { private Long id; private String name; private Integer age; private String email; } 

3.这里注意MybatisPlusApplication这里需要添加扫描mapper文件
@MapperScan(“com.xyj.mapper”)对应你的包位置

package com.xyj; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; //扫描mapper文件夹 @MapperScan("com.xyj.mapper") @SpringBootApplication public class MybatisPlusApplication { public static void main(String[] args) {         SpringApplication.run(MybatisPlusApplication.class, args); } } 

4.application.properties的相关配置，与之前没有什么不同

 spring.datasource.username=root spring.datasource.password=123456 spring.datasource.url=jdbc:mysql://localhost:3306/mybatis_plus?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver  

5.测试一下在MybatisPlusApplicationTests

package com.xyj; import com.xyj.mapper.UserMapper; import com.xyj.pojo.User; import org.junit.jupiter.api.Test; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.context.SpringBootTest; import java.util.List; @SpringBootTest class MybatisPlusApplicationTests { //继承basemapper，所有方法来自父类 @Autowired private UserMapper userMapper; @Test void contextLoads() { //查询全部         List<User> users = userMapper.selectList(null);         users.forEach(System.out::println); } } 

只需几步就可以完成CRUD操作

添加操作

 @Test public void testInsert(){         User user = new User();         user.setName("xyj");         user.setAge(18);         user.setEmail("1550213743@qq.com"); int result = userMapper.insert(user);//帮我们自动生成id         System.out.println(result);         System.out.println(user);          System.out.println(user.getId()); } 

更新操作

//通过条件自动拼接动态sql @Test public void testUpdate(){         User user = new User();         user.setId( 5L);         user.setAge(60);         user.setName("青青草原");         user.setEmail("qingqingcaoyuan@qq.com"); int result = userMapper.updateById(user);         System.out.println(result); }