Mybatis-Plus快速開始
阿新 • • 發佈:2020-10-05
Mybatis-Plus雖然官網上有一個快速開始,但是實際操作有點問題,所以,自己寫了一個。
版本說明
如果用其他軟體版本可能會有部分差異
mybatis-plus:3.0.5
springboot:2.3.4
mysql:5.1.47
新建資料庫和表
- 新建一個數據庫
mybatis_plus
- 新建一個表和新增資料
create table user( id BIGINT(20) not null COMMENT "主鍵ID" ,name VARCHAR(30) COMMENT "姓名" ,age INT(11) COMMENT "年齡" ,email VARCHAR(50) COMMENT "郵箱" ,PRIMARY KEY(id) ); INSERT INTO `mybatis_plus`.`user` (`id`, `name`, `age`, `email`) VALUES ('1', 'Jane', '10', '[email protected]'); INSERT INTO `mybatis_plus`.`user` (`id`, `name`, `age`, `email`) VALUES ('2', 'Jack', '18', '[email protected]'); INSERT INTO `mybatis_plus`.`user` (`id`, `name`, `age`, `email`) VALUES ('3', 'Tom', '20', '[email protected]'); INSERT INTO `mybatis_plus`.`user` (`id`, `name`, `age`, `email`) VALUES ('4', 'Samdy', '15', '[email protected]'); INSERT INTO `mybatis_plus`.`user` (`id`, `name`, `age`, `email`) VALUES ('5', 'kangkanhg', '16', '[email protected]');
初始化專案
IDEA使用Spring Initializr新建一個springboot專案,使用版本2.3.4.RELEASE
新增依賴
<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> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> <!--mybatis-plus--> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.0.5</version> </dependency> <!--mysql 可以確定mysql的版本5還是8--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!--lombok用來簡化實體類--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </dependency> </dependencies>
配置
在 application.properties 配置檔案中新增 mysql 資料庫的相關配置:
注意如果mysql是8版本就要加一個時區?serverTimezone=GMT%2B8
#mysql資料庫連線
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis_plus
spring.datasource.username=root
spring.datasource.password=123456
編碼
實體類
package com.jmu.pojo; import lombok.Data; @Data public class User { private long id; private String name; private int age; private String email; }
Mapper類
package com.jmu.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.jmu.pojo.User;
import org.springframework.stereotype.Repository;
@Repository
public interface UserMapper extends BaseMapper<User> {
}
掃描mapper
在mapper的啟動類中新增
package com.jmu;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("com.jmu.mapper")
@SpringBootApplication
public class MpApplication {
public static void main(String[] args) {
SpringApplication.run(MpApplication.class, args);
}
}
測試
package com.jmu;
import com.jmu.mapper.UserMapper;
import com.jmu.pojo.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 MpApplicationTests {
@Autowired
private UserMapper userMapper;
@Test
void contextLoads() {
List<User> all= userMapper.selectList(null);
for (User user : all) {
System.out.println(user);
}
}
}