MyBatis-Plus快速入门

以SpingBoot整合MyBatis-Plus为例，数据库采用MySQL

创建数据表并添加数据

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)
);
​
DELETE FROM user;
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');

创建SpringBoot工程

 添加依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.8</version>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

配置数据源

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis_plus?serverTimezone=UTC
    username: root
    password: 1234

创建实体类

package com.cas.entity;
​
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;
    
    //idea中使用Alt+Insert快捷键
    //生成Getter、Setter和toString方法...
}

创建Mapper

package com.cas.dao;
​
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.cas.entity.User;
import org.apache.ibatis.annotations.Mapper;
​
//继承BaseMapper以获取单表的CRUD方法
@Mapper
public interface UserMapper extends BaseMapper<User> {
​
}

开始测试

package com.cas;
​
import com.cas.dao.UserMapper;
import com.cas.entity.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 ApplicationTests {
    @Autowired
    UserMapper userMapper;
​
    @Test
    public void testSelect() {
        List<User> users = userMapper.selectList(null);
        users.forEach(System.out::println);
    }
}

测试结果如下

参考资料

1. 快速开始 | MyBatis-Plus (baomidou.com)

2. MyBatisPlus-01-MybatisPlus入门案例_哔哩哔哩_bilibili