我创建了两个实体Book并且Book_Category具有一对多关系。当我发出时BookCategoryRepository.findAll()，我希望hibernate状态使用“
INNER JOIN”查询。但是它只是发出查询以从Book_Category获取数据。

我缺少什么？我该怎么做使hibernate问题的JOIN查询？

Book.java

@Entity
public  class Book {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    private String name;

    @ManyToOne
    @JoinColumn(name = "book_category_id")
    private BookCategory bookCategory;
}

BookCategory.java

@Entity
@Table(name = "book_category")
public  class BookCategory {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    private String name;
    @OneToMany(mappedBy = "bookCategory", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    private Set<Book> books;
}

BookCategoryRepository.java

public  interface BookCategoryRepository extends JpaRepository<BookCategory, Integer> {
}


bookCategoryRepository.findAll()