mybatis-plus快速开始 mysql

快速开始

官方的介绍：https://baomidou.com/guide/quick-start.html

更改数据库的使用，改成mysql

强推B站狂神说：https://space.bilibili.com/95256449

环境配置：

• mysql8.0+

• idea 2019

• jdk 1.8

创建一个maven-quickStart项目

略

创建数据库

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');

配置文件

添加依赖：pom.xml

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.4.0</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>


<properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </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>3.4.1</version>
        </dependency>

        <!-- mysql 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- c3p0 数据源 -->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.5</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>

    </dependencies>

application.yml

## 数据源配置
spring:
  datasource: # 数据库的数据配置
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis_plus?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false
    username: root
    password: 123456

## 显示dao 执⾏sql语句
logging:
  level:
    com.ppl.mybatisp.mapper: debug # 改成你的dao接口文件所在包路径可以打印出sql语句

进行案例测试：

User.java

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

UserMapper.java

public interface UserMapper extends BaseMapper<User> {
    
}

MybatispApplication.java

@SpringBootApplication
@MapperScan("com.ppl.mybatisp.mapper")
public class MybatispApplication {

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

}

MybatispApplicationTests.java

@SpringBootTest(classes = {MybatispApplication.class})
@RunWith(SpringRunner.class)
class MybatispApplicationTests {

    @Resource
    private UserMapper userMapper;

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

    @Test
    void testInsert(){
        User user = new User();
        user.setAge(10);
        user.setEmail("3423423@qq.com");
        user.setName("ppl");
        userMapper.insert(user);
        List<User> users = userMapper.selectList(null);
        users.forEach(System.out::println);
    }

}