在 JPA 中将实体类行设为只读

Question

当我只映射一个表时，我可以使用 JPA 获取值

现在当我去映射相关表时，我得到了错误

  Only one may be defined as writable, all others must be specified read-only.
  Mapping: org.eclipse.persistence.mappings.OneToOneMapping[userId1]

我正在使用 [EclipseLink-0] (Eclipse Persistence Services - 2.0.1.v20100213-r6600)

在其中一个子表中我有这个代码

@OneToMany(cascade = CascadeType.ALL, mappedBy = "albumId")
private Collection<Images> imagesCollection;
@JoinColumn(name = "user_id", referencedColumnName = "User_ID")
@ManyToOne(optional = false)
private Roleuser userId;
@JoinColumn(name = "album_image", referencedColumnName = "image_id")
@ManyToOne
private Images albumImage;
@JoinColumn(name = "album_image", referencedColumnName = "image_id")
@ManyToOne
private Images albumImage1;
@JoinColumn(name = "user_id", referencedColumnName = "User_ID")
@ManyToOne(optional = false)
private Roleuser userId1;

我必须在此代码中进行哪些更改才能使字段为只读？

或者有没有更好的解决方法来不将这些字段设为只读？

Answer 1

您有两个使用相同外键字段的多对一关系。这没有意义，它们会是同一个对象吗？

@JoinColumn(name = "album_image", referencedColumnName = "image_id")
@ManyToOne
private Images albumImage;
@JoinColumn(name = "album_image", referencedColumnName = "image_id")
@ManyToOne
private Images albumImage1;

您应该有两个不同的外键字段，即albumImage 和albumImage1。