Hibernate OGM: How to store a List?

Question

Is it possible to store List with Hibernate OGM and mongodb without creating a Entity for type Double.

Example:

@Entity
public class Series extends Default {
    private List<Double> results;

Gives the following exception:

Caused by: org.hibernate.MappingException: Could not determine type for: java.util.List, at table: Series, for columns: [org.hibernate.mapping.Column(results)]

If I add a @OneToMany relation to the List I have to create a Entity for Double otherwise it will throw:

Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class

How do you expect to store an unfixed-size list of doubles in the database? — Zircon, Feb 23 '17 at 16:54

score 2 · Accepted Answer · answered Feb 24 '17 at 10:41

2

You need to use the annotation @ElementCollection.

Like this:

@ElementCollection
private List<Double> results;

answered Feb 24 '17 at 10:41

Davide D'Alto

7,421
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score -1 · Answer 2 · answered Feb 23 '17 at 16:56

-1

You can use UserType to convert your List<Double> to a String, but you will lose the availability to use aggregates functions over this field.

answered Feb 23 '17 at 16:56

Sergio Lema

1,491
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I don't think that's the issue, per docs https://docs.jboss.org/hibernate/stable/ogm/reference/en-US/html_single/?v=5.0 it seems that the collection should be initialized as mentioned by @Zircon – xiumeteo Feb 23 '17 at 17:00

Hibernate OGM: How to store a List?

2 Answers2