Question

我想在两个表BookStock和Book之间进行一对多映射，但是我得到以下异常

Exception in thread "main" org.hibernate.MappingException: Could not determine type for: java.util.List, at table: book_stock, for columns: [org.hibernate.mapping.Column(books)]

bookStock实体

@Entity
@Table(name = "book_stock")
public class BookStock {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private Long stock;
    private List<Book> books;

    @Column(name = "id")
    public Long getId() {
        return id;
    }

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

    @Column(name = "stock")
    public Long getStock() {
        return stock;
    }

    public void setStock(Long stock) {
        this.stock = stock;
    }

    @OneToMany
    @PrimaryKeyJoinColumn
    public List<Book> getBooks() {
        return books;
    }

    public void setBooks(List<Book> books) {
        this.books = books;
    }
}

图书实体

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

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String bookName;
    private BigDecimal price;
    private BookStock bookStock;

    @Column(name = "id")
    public Long getId() {
        return id;
    }

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

    @Column(name = "book_name")
    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    @Column(name = "price")
    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    @ManyToOne
    public BookStock getBookStock() {
        return bookStock;
    }

    public void setBookStock(BookStock bookStock) {
        this.bookStock = bookStock;
    }
}

Example类是

public class transactionsExample {

    public static void main(String[] args) {
        AnnotationConfiguration configuration = new AnnotationConfiguration();
        configuration.configure();
        configuration.addAnnotatedClass(Book.class);
        configuration.addAnnotatedClass(BookStock.class);
        configuration.setNamingStrategy(ImprovedNamingStrategy.INSTANCE);
        SessionFactory sessionFactory = configuration.buildSessionFactory();
        Session session = sessionFactory.openSession();

        session.beginTransaction();
        Book book1 = EntityBuilder.book().withISBN("21234").withName("Anario").withPrice(25.90).purchase();
       session.save(book1);
        session.getTransaction().commit();
    }
}

这种关系出了什么问题？

Answer 1

它找不到所有注释，因为您正在注释两个字段和方法。您只需使用一种策略。在你的情况下，首先看到id field 中的@Id注释，这就是为什么get-methods中的注释没有效果。结果，hibernate正确地假设了

List<Book> books;

未映射。如果您还将注释从id-field移动到getId-method（对于两个实体），问题就解决了。

关于修复映射的其他问题，请参阅下面的评论。

Hibernate映射异常：无法确定列的类型：[org.hibernate.mapping.Column]

1 个答案: