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Re: [eclipselink-users] primary key (@id) in one-to-many relation
|
Yes, that is the way it must be done. You should have a Basic @Id attribute
called rowNum in your CClsItem class. What error are you getting doing
this?
Perhaps include your complete mappings including how the @Id is mapped.
Holger Rieß-2 wrote:
>
>
> Hello,
>
> I hope, this is a newbie question:
> Is it possible to use a primary key (@id) field in an one-to-many
> relation?
>
> My first class CClsItem, the 'one' part of the relation:
>
> @Entity
> @Table(name="C_CLS_ITEMS")
> public class CClsItem implements Serializable {
> ...
> //bi-directional many-to-one association to Note
> @OneToMany(mappedBy="CClsItem")
> public List<Note> getNotes() {
> return this.notes;
> }
> ...
> }
>
> My second class, the 'many' part of the relation:
> @Entity
> @Table(name="NOTES")
> public class Note implements Serializable {
> ...
> //bi-directional many-to-one association to CClsItem
> @ManyToOne
> @JoinColumn(name="NOTESRECID", referencedColumnName="ROWNUMBER",
> nullable=false)
> public CClsItem getCClsItem() {
> return this.CClsItem;
> }
> ...
> }
> There should be a join NOTES.NOTESRECID=C_CLS_ITEMS.ROWNUMBER. But the
> field C_CLS_ITEMS.ROWNUMBER is the primary field. The eclipse tool
> 'generate entities from tables' removes my @id annotated field ROWNUMBER,
> if I use it in a relation.
>
> I'm afraid I dont understand the JPA fundamentals?
>
>
-----
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