快速开始

快速开始

1. 创建数据库mybatis-puls

2. 创建user表

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');

3. 创建springboot项目，导入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.saxon</groupId>
    <artifactId>mybatisplus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatisplus</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</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>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.1.tmp</version>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.19</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.4.0</version>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

注意点：尽量不要同时导入mybatis-plus 和 mybatis ,出现版本差异。

4. 配置 连接数据库

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/mybatis-puls?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
    driver-class-name: com.mysql.cj.jdbc.Driver

5. 编写实体类

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

6. 编写Mapper类

//继承最基本的BaseMapper
@Repository //代表持久层
public interface UserMapper extends BaseMapper<User> {
//所有的crud已经编写完成。
}

7. 创建启动类

@SpringBootApplication
@MapperScan("com.saxon.mapper")
public class MybatisplusApplication {

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

}

8. 测试
   查询全部用户

@SpringBootTest
class MybatisplusApplicationTests {

    @Autowired
    private UserMapper mapper;

    @Test
    void contextLoads() {
        //参数是一个Wrapper，条件构造器，这里先设置为null
        List<User> users = mapper.selectList(null);
        users.forEach(System.out::println);//打印输出
    }

}

通过以上几个简单的步骤，我们就实现了 User 表的 CRUD 功能，甚至连 XML 文件都不用编写！
从以上步骤中，我们可以看到集成MyBatis-Plus非常的简单，只需要引入 starter 工程，并配置 mapper 扫描路径即可。
但 MyBatis-Plus 的强大远不止这些功能，想要详细了解 MyBatis-Plus 的强大功能？那就继续往下看吧！（官网原话）