markdown JPA - DTO作为结果

Posted 2021-05-05

DTO:

```java
package app.dto;

public class UserNameDTO {

    private Long id;
    private String name;

    public UserNameDTO(Long id, String name) {
        this.id = id;
        this.name = name;
    }

    public Long getId() {
        return id;
    }

    public String getName() {
        return name;
    }
}

```

Repository:
```java
package app.repositories;

import app.entities.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface UserRepository extends JpaRepository<User, Long> {

    @Query("SELECT new app.dto.UserNameDTO(u.id, u.name) FROM User u WHERE u.name = :name")
    List<UserNameDTO> retrieveUsernameAsDTO(@Param("name") String name);
    
}
```