Question

I have a named native query and I am trying to map it to the return results of the named native query. There is a field that I want to add to my entity that doesn’t exist in the table, but it will exist in the return result of the query. I guess this would be the same with a stored proc…

How do you map the return results of a stored proc in JPA?…

How do you even call a stored proc?

here is an example query of what I would like to do…

select d.list_id as LIST_ID, 0 as Parent_ID, d.description  from EPCD13.distribution_list d

The Result will be mapped to this entity…

public class DistributionList implements Serializable {
    @Id
    @Column(name="LIST_ID")
    private long listId;

    private String description;

    private String owner;

    private String flag;

    @Column(name="PARENT_ID", nullable = true)
    private long parentID;
}

parent ID is not in any table in my database. I will also need to use this entity again for other calls, that have nothing to do with this call, and that will not need this parent_id? Is there anything in the JPA standard that will help me out?

Answer 1

If results from database are not required for further manipulation, just for preview, you can consider using database view or result classes constructor expression.

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If entities retrieved from database are required for further manipulation, you can make use of multiple select expression and transient fields.

1. Replace @Column annotation with @Transient annotation over parentID.
2. After retrieving multiple columns from database, iterate over results and manually set parentID.