使实体类行只读在JPA

Question

我为能够使用JPA时，我只映射到一个表

我们得到的值时，我已经映射相关表出现错误

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

我米使用[的EclipseLink-0]（Eclipse持久服务 - 2.0.1.v20100213-r6600）

在子表我有此代码

@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; 

之一

在此代码中我必须做什么更改才能使字段为只读？

还是有没有更好的解决方法不使这些领域只读？

Answer 1

您有两个使用相同外键字段的ManyToOne关系。这没有意义，它们会是同一个对象？

@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。