MybatisPlus學習-02-快速入門
阿新 • • 發佈：2021-09-07
MybatisPlus學習-02-快速入門
步驟
建立資料庫mybatisplus
建立user表
CREATE TABLE user ( id BIGINT(20) NOT NULL COMMENT '主鍵ID', name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名', age INT(11) NULL DEFAULT NULL COMMENT '年齡', email VARCHAR(50) NULL DEFAULT NULL COMMENT '郵箱', PRIMARY KEY (id) ); INSERT INTO user (id, name, age, email) VALUES (1, 'Jone', 18, '[email protected]'), (2, 'Jack', 20, '[email protected]'), (3, 'Tom', 28, '[email protected]'), (4, 'Sandy', 21, '[email protected]'), (5, 'Billie', 24, '[email protected]');
編寫專案，初始化專案！建立springboot專案
匯入依賴
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.32</version> </dependency> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.0.5</version> </dependency>
說明：我們使用mybatis-plus可以節省我們大量的程式碼，儘量不要同時匯入mybatis和mybatis-plus。
連線資料庫
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=hyg1230
spring.datasource.url=jdbc:mysql://localhost:3306/mybatisplus
pojo-dao-service-controller
pojo
import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @NoArgsConstructor @AllArgsConstructor public class User { private Long id; private String name; private Integer age; private String email; }
mapper介面
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.gui.pojo.User;
import org.springframework.stereotype.Repository;
//在對應Mapper上繼承基本的類BaseMapper
@Repository
public interface UserMapper extends BaseMapper<User> {
}
注意點：需要在主啟動類上掃描mapper包的介面
@MapperScan("com.gui.mapper")
測試類測試
@Autowired
private UserMapper userMapper;
@Test
void contextLoads() {
//引數是一個Wrapper，條件構造器
List<User> users = userMapper.selectList(null);
users.forEach(System.out::println);
}