Question

我创建了一个带有实体的JHipster Monolithic应用程序：profile，follow＆amp; voyage导致以下架构：

我通过添加PROFILE实体扩展了JHI_USER。
每个用户可以关注零个或多个其他用户（以下）。
用户拥有零次或多次航程（VOYAGES）

在我的网络Angular应用程序中，我想显示特定用户关注的用户的航程列表。以下SQL查询将为我提供所需的结果集：

SELECT PROFILE.HANDLE, VOYAGE.NAME
FROM PROFILE, VOYAGE, FOLLOWING
WHERE FOLLOWING.USER_ID = 4
AND VOYAGE.USER_ID = PROFILE.USER_ID
AND PROFILE.USER_ID = FOLLOWING.FOLLOWING_ID

在我的JHipster应用程序中创建返回此结果集的REST端点需要哪些步骤？

我是否需要执行以下操作？

为结果集
创建一个执行查询的新Repository类
在我的Controller中创建一个端点，该端点调用Repository以将结果检索为我的实体列表

我是Spring JPA的新手，并且一直在努力实现它。

===更新===

以下是我项目中的实体类：

＆＃39;简介＆＃39;实体：

/**
 * A Profile.
 */
@Entity
@Table(name = "profile")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class Profile implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
    @SequenceGenerator(name = "sequenceGenerator")
    private Long id;

    @NotNull
    @Column(name = "handle", nullable = false)
    private String handle;

    @Column(name = "bio")
    private String bio;

    @OneToOne
    @JoinColumn(unique = true)
    private User user;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getHandle() {
        return handle;
    }

    public Profile handle(String handle) {
        this.handle = handle;
        return this;
    }

    public void setHandle(String handle) {
        this.handle = handle;
    }

    public String getBio() {
        return bio;
    }

    public Profile bio(String bio) {
        this.bio = bio;
        return this;
    }

    public void setBio(String bio) {
        this.bio = bio;
    }

    public User getUser() {
        return user;
    }

    public Profile user(User user) {
        this.user = user;
        return this;
    }

    public void setUser(User user) {
        this.user = user;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Profile profile = (Profile) o;
        if (profile.id == null || id == null) {
            return false;
        }
        return Objects.equals(id, profile.id);
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(id);
    }

    @Override
    public String toString() {
        return "Profile{" +
            "id=" + id +
            ", handle='" + handle + "'" +
            ", bio='" + bio + "'" +
            '}';
    }
}

＆＃39;关注＆＃39;实体：

/ ** *以下。 * / @实体 @Table（姓名=＆＃34;以下＆＃34;） @Cache（usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE） public class以下实现Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
    @SequenceGenerator(name = "sequenceGenerator")
    private Long id;

    @OneToOne
    @JoinColumn(unique = true)
    private User following;

    @ManyToOne
    private User user;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public User getFollowing() {
        return following;
    }

    public Following following(User user) {
        this.following = user;
        return this;
    }

    public void setFollowing(User user) {
        this.following = user;
    }

    public User getUser() {
        return user;
    }

    public Following user(User user) {
        this.user = user;
        return this;
    }

    public void setUser(User user) {
        this.user = user;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Following following = (Following) o;
        if (following.id == null || id == null) {
            return false;
        }
        return Objects.equals(id, following.id);
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(id);
    }

    @Override
    public String toString() {
        return "Following{" +
            "id=" + id +
            '}';
    }
}

＆＃39; Voyage＆＃39;实体：

/**
 * A Voyage.
 */
@Entity
@Table(name = "voyage")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class Voyage implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
    @SequenceGenerator(name = "sequenceGenerator")
    private Long id;

    @NotNull
    @Column(name = "name", nullable = false)
    private String name;

    @NotNull
    @Column(name = "start_date", nullable = false)
    private ZonedDateTime startDate;

    @Column(name = "distance")
    private Integer distance;

    @ManyToOne
    private User user;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public Voyage name(String name) {
        this.name = name;
        return this;
    }

    public void setName(String name) {
        this.name = name;
    }

    public ZonedDateTime getStartDate() {
        return startDate;
    }

    public Voyage startDate(ZonedDateTime startDate) {
        this.startDate = startDate;
        return this;
    }

    public void setStartDate(ZonedDateTime startDate) {
        this.startDate = startDate;
    }

    public Integer getDistance() {
        return distance;
    }

    public Voyage distance(Integer distance) {
        this.distance = distance;
        return this;
    }

    public void setDistance(Integer distance) {
        this.distance = distance;
    }

    public User getUser() {
        return user;
    }

    public Voyage user(User user) {
        this.user = user;
        return this;
    }

    public void setUser(User user) {
        this.user = user;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Voyage voyage = (Voyage) o;
        if (voyage.id == null || id == null) {
            return false;
        }
        return Objects.equals(id, voyage.id);
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(id);
    }

    @Override
    public String toString() {
        return "Voyage{" +
            "id=" + id +
            ", name='" + name + "'" +
            ", startDate='" + startDate + "'" +
            ", distance='" + distance + "'" +
            '}';
    }
}

Answer 1

按照评论中的建议修改架构后，您需要添加2个查询：

1.VoyageRepository：

List<Voyage> findByProfileIn(Collection<Profile> profiles);

2.ProfileRepository

List<Profile> findByFollowingID(long Id);

然后在您的Voyage服务中结合这两个查询：

return voyageRepository.findByProfileIn(profileRepository.findbyFollowingId(id));

然后在你的VoyageRessource中公开它。

Answer 2

我的工作是：

1.修改架构，使“配置文件”具有一对多与'跟随'和'的关系'航程'，即删除了 JHI_USER＆amp;的关系'跟随'和'航程'

2.在VoyageRepository

中定义以下查询

public interface VoyageRepository extends JpaRepository<Voyage,Long> {
    @Query("select v.name, v.profile.handle from Voyage v, Following f where f.profile.user.id = 4 and f.following.id = v.profile.id")

    List<Voyage> getFeed();
}

我已经在上面的代码中硬编码了id值（4），因为我还没有弄清楚如何将参数传递给查询。 JPA是精神上的弯曲！

从我的REST API中检索表连接结果集

2 个答案: