官方文档

• https://mybatis.plus/guide/

添加maven依赖

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.0</version>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

配置

配置数据源相关信息

spring:
  datasource:
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test

使用

数据表如下

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');

1.定义实体类

com.lyp.entity.User

@Data
public class User
{
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

2.定义mapper接口

与jpa类似，mybatis提供了默认的CRUD功能，对于简单的单表查询，无需配置mapper映射文件(或者基于注解的sql)。

com.lyp.mapper.UserMapper

@Mapper
public interface UserMapper extends BaseMapper<User>
{

}

3.执行CRUD

com.lyp.controller.MyController

@RestController
public class MyController
{
    private final UserMapper userMapper;

    @Autowired
    public MyController(UserMapper userMapper)
    {
        this.userMapper = userMapper;
    }

    @GetMapping("/users")
    public Object users()
    {
        List<User> users = userMapper.selectList(null);
        return users;
    }
}