企业微信官方网站,外贸网站建设电话,微信小程序开发需要学什么,上海临港公司注册最新规定MyBatis-Plus (opens new window)#xff08;简称 MP#xff09;是一个 MyBatis (opens new window)的增强工具#xff0c;在 MyBatis 的基础上只做增强不做改变#xff0c;为简化开发、提高效率而生。 全新的 MyBatis-Plus 3.0 版本基于 JDK8#xff0c;提供了 lambda 形… MyBatis-Plus (opens new window)简称 MP是一个 MyBatis (opens new window)的增强工具在 MyBatis 的基础上只做增强不做改变为简化开发、提高效率而生。 全新的 MyBatis-Plus 3.0 版本基于 JDK8提供了 lambda 形式的调用所以安装集成 MP3.0 要求如下
JDK 8Maven or Gradle Spring Boot 2.5MySql、Oracle、SQLServer、、
一、数据表设计
IDNameSexAgeGrade1小明男1262小红女116
建表语句如下
DROP TABLE IF EXISTS user;CREATE TABLE user
(id BIGINT NOT NULL COMMENT 主键ID,name VARCHAR(30) NULL DEFAULT NULL COMMENT 姓名,sex VARCHAR(30) NULL DEFAULT NULL COMMENT 性别,age INT NULL DEFAULT NULL COMMENT 年龄,grade VARCHAR(50) NULL DEFAULT NULL COMMENT 年级,PRIMARY KEY (id)
);
然后插入数据
INSERT INTO user (id, name, age, email) VALUES
(1, 小明, 男12, 6),
(2, 小红, 女,11, 6),二、开发实例
1、引入依赖 parentgroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-parent/artifactIdversion3.1.5/versionrelativePath//parentdependenciesdependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter/artifactId/dependencydependencygroupIdcom.h2database/groupIdartifactIdh2/artifactIdscoperuntime/scope/dependencydependencygroupIdcom.baomidou/groupIdartifactIdmybatis-plus-spring-boot3-starter/artifactIdversion3.5.4version/dependencydependencygroupIdmysql/groupIdartifactIdmysql-connector-java/artifactIdversion8.0.26/version/dependency/dependencies 2、配置数据源 在application.yaml 中配置相关配置信息:
spring:datasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://127.0.0.1:3306/Dokerusername: rootpassword: root
3、开发实例 3.1 实体类
Data
TableName(user)
public class User {TableId(type IdType.AUTO)private Long id;TableField(name)private String name;private String sex;private Integer age;private String grade;
} TableName:
描述表名注解标识实体类对应的表使用位置实体类
TableId
描述主键注解使用位置实体类主键字段
TableField
描述字段注解非主键
3.2 UserMapper接口 ?xml version1.0 encodingUTF-8 ?
!DOCTYPE mapper PUBLIC -//mybatis.org//DTD Mapper 3.0//EN http://mybatis.org/dtd/mybatis-3-mapper.dtd
mapper namespacecom.UserMapperSELECT * FROM user WHERE name #{name}
/mapper
public interface UserMapper extends BaseMapperUser {Select(select * from user)ListUser getAllUser();} 3.3 Service层接口
import com.baomidou.mybatisplus.extension.service.IService;// UserService 继承 IService 接口
public interface UserService extends IServiceUser{ListUser getAllUser();
}
Service
public class UserServiceImpl extends ServiceImplUserMapper, User implements UserService {Autowiredprivate UserMapper userMapper;public ListUser getAllUser(){return userMapper.getAllUser();}
}
3.4 在 Spring Boot 启动类中添加 MapperScan 注解扫描 Mapper 文件夹
SpringBootApplication
MapperScan(com.mapper)
public class Application {public static void main(String[] args) {SpringApplication.run(Application.class, args);}}
