在JPA中将实体类行设为只读

Question

I m able to get values using JPA when i have only mapped one table

Now when i have gone for mapping related tables i get the error

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

I m using [EclipseLink-0] (Eclipse Persistence Services - 2.0.1.v20100213-r6600)

In one of the child tables i have this code

@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;

What changes i have to do in this code to make the fields read-only?

or are there any better workaround for not making these fields read only?

Answer 1

You have two ManyToOne relationships using the same foreign key field. This does not make sense, they will be the same object?

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

You should have two different foreign key fields, ie albumImage and albumImage1.