mybatis-plus示例(mysql)

一、准备工作

1. mysql 安装

下载地址:https://downloads.mysql.com/archives/community/
我选择的版本是5.7.8rc

2. 数据库准备

-- 创建数据库
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)
);

-- 插入数据
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');

3. maven依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
        <relativePath/>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
    </dependencies>

4. 配置

在resources文件夹中添加application.yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/hx?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: 123456

二、代码

1. 实体类

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

2. Mapper

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

3. spring boot启动类

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

4. 测试类

@SpringBootTest
public class TestSelect {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void selectList() {
        List<User> users = userMapper.selectList(null);
        users.forEach(System.out::println);
    }
}

5. 结果

User(id=1, name=Jone, age=18, email=test1@baomidou.com)
User(id=2, name=Jack, age=20, email=test2@baomidou.com)
User(id=3, name=Tom, age=28, email=test3@baomidou.com)
User(id=4, name=Sandy, age=21, email=test4@baomidou.com)
User(id=5, name=Billie, age=24, email=test5@baomidou.com)