Question

我正在尝试创建一个库 API。我有一个图书实体和一个会员实体。在 Book 类中，我创建了一个 of Member 类来检查 Book 是否提供给 Member。成员类也是如此。

但问题是我这样做时出错

Could not determine type for: com.example.demo.Member, at table: book, for columns: [org.hibernate.mapping.Column(member)]
Could not determine type for: com.example.demo.Member, at table: book, for columns: [org.hibernate.mapping.Column(member)]

我找到了许多与此主题相关的答案，但是... 他们都在使用集合中的类列表我应该给它们添加什么注释？？

Book.java

@Entity
public class Book {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private int page;
    private String name;
    private String author;
    private String publisher;
    private Date dateOfBookRegistration;
    private Member member;
    
    // getters setters ...
}

会员

@Entity
public class Member {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private String name;
    private Date dateOfRegistration;
    private Date dateOfBirth;
    private Date dateOfGettingBook;
    private Book book;

    // getters setters ...
}

Answer 1

您缺少两个实体之间的关联。例如，根据您的需要，您可以使用单向一对一关联：

通过如下更改 Book 实体的代码...

@OneToOne
@JoinColumn(name = "id")
private Member member

成员实体的 id 将作为外键存储在书本记录中。

弹簧靴 |在实体类

1 个答案: