[英]How to define custom findAll methods in JpaRepository?
我有兩個 api 端點:
/api/posts
- 獲取分頁帖子列表/api/countries/{country}/posts
- 按國家/地區獲取分頁帖子列表所以我有以下實體:
@Data
@Entity
@Table(name = "posts")
@EntityListeners(AuditingEntityListener.class)
@NamedEntityGraph(
name = "Post.Resource",
attributeNodes = @NamedAttributeNode("country")
)
public class Post {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
private String title;
private String body;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "country_id")
private Country country;
@Column(name = "published_at")
private LocalDateTime publishedAt;
@CreatedDate
@Column(name = "created_at")
private LocalDateTime createdAt;
@LastModifiedDate
@Column(name = "updated_at")
private LocalDateTime updatedAt;
public boolean isPublished() {
return publishedAt != null;
}
public boolean isDraft() {
return !isPublished();
}
}
我已經定義了以下存儲庫。 請注意,我是如何為最后兩個方法定義實體圖的,我需要這樣,因為我不想覆蓋findAll()
方法,因為將來我需要加載沒有任何關系的帖子。 還有一件事我希望它成為謂詞,以便在各種不同的服務中我可以重用方法,而不是為每個查詢創建方法......
@Repository
public interface PostRepository extends JpaRepository<Post, Long>,
JpaSpecificationExecutor<Post>,
QuerydslPredicateExecutor<Post>
{
@EntityGraph("Post.Resource")
Optional<Post> findPostResourceById(long id);
@Query("SELECT post FROM Post post")
@EntityGraph("Post.Resource")
Page<Post> findAllPostResources(Pageable pageable);
@Query("SELECT post FROM Post post")
@EntityGraph("Post.Resource")
Page<Post> findAllPostResources(Predicate predicate, Pageable pageable);
}
問題是當我使用謂詞和可分頁 arguments 調用findAllPostResources
時:
public Page<Post> getAllPostsByCountryPaginated(long countryId, Pageable pageable) {
return postRepository.findAllPostResources(QPost.post.country.id.eq(countryId), pageable);
}
它忽略謂詞參數並執行以下查詢:
SELECT
post0_.id AS id1_13_0_,
country1_.id AS id1_3_1_,
post0_.body AS body2_13_0_,
post0_.country_id AS country_7_13_0_,
post0_.created_at AS created_3_13_0_,
post0_.published_at AS publishe4_13_0_,
post0_.title AS title5_13_0_,
post0_.updated_at AS updated_6_13_0_,
country1_.alpha2_code AS alpha2_3_1_,
country1_.alpha3_code AS alpha3_3_1_,
country1_.created_at AS created_4_3_1_,
country1_.name AS name5_3_1_,
country1_.updated_at AS updated_6_3_1_
FROM
posts post0_
LEFT OUTER JOIN countries country1_ ON
post0_.country_id = country1_.id
LIMIT ?
如您所見, SQL ( WHERE country_id =?
)中沒有 WHERE 原因。
那么,如何創建 findAll() 方法並定義謂詞、分頁以及在 JpaRepository 中使用什么實體圖? 或者這是無法通過這種方式實現的,我需要創建自定義存儲庫實現?
但你有這個查詢:
LEFT OUTER JOIN countries country1_ ON
post0_.country_id = country1_.id
LIMIT
與“where country_id =”不一樣嗎? 您是否在示例數據庫上運行此查詢並查看您得到了什么? 也許它只是工作正常。
另外,我認為,你可以說
findAllPostResourcesByCountryId(long countryId);
抱歉,我很想發表評論而不是回答,但我沒有足夠的聲譽。
我找到了解決我的問題的方法:如何同時使用 Predicate、Pageable 和 EntityGraph 的方法,答案是使用以下庫:
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