用于以一对多关系获取某些项目的 HQL 查询

Question

我在互联网上搜索了所有内容，但没有找到答案。

我有两个类之间的 oneToMany 关系，我想获得列表的一部分。

@Entity
@Table(name = "author")
class Author {
     @Id
     private Long id;

     @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
     @JoinColumn(name = "AUTHOR_ID", referencedColumnName = "id")
     private List<Book> books = new ArrayList<>();

}

@Entity
@Table(name="book")
class Book {

    @Column
    private Integer year;

    @Column
    private Integer position;

}

我想从特定作者那里获得特定年份且低于特定职位的所有书籍

@Query(From Book b where b.year=:year and b.position<:position and b.authorId=:id)
List<Book> getAllBooks(Integer year, Integer position, Long id)

我也试过了

@Query(From Book b where b.year=:year and b.position<:position and b.id in (select a.books.id from author a where a.id:=id)

谢谢你帮助我

Answer 1

如果您尝试使用 JPQL 设置查询，在我看来它应该是......

@Query("SELECT b FROM Book b WHERE b.year = :year and b.position < :position and b.authorId = :id")

更新

抱歉——我之前通过复制和修改您的第一个示例来回答。我错过了加入。

这可能行得通...

@Query("SELECT a.books b FROM Author a WHERE b.year = :year AND b.position < :position AND a.authorId = :id")

你也可以试试这个……

@Query("SELECT b FROM Book b WHERE b.year = :year AND b.position < :position AND b IN (SELECT a.books FROM Author a WHERE a.id = :id")