how to query ElementCollection of String (Hibernate OGM 4.2)

manaveed · **Joined:** Thu Aug 27, 2015 3:40 pm **Posts:** 2

I have this Users class

Code:

@Entity
@Table(name = "Users")
public class Users implements  Serializable {

    private static final long serialVersionUID = -5638228567536191397L;

    @Id
    @Column(name = "_id")
    private ObjectId _id;
    private String name;

    @ElementCollection
    private List<String> mail;

//getter, setter ...
}

following is a json from mongodb Users collection.
where mail is a field of string array

Code:

{ 
    "_id" : ObjectId("55c59b30a5c2073240ffc274"), 
    "name" : "john doe"
    "mail" : ["abc@blah.com"]
}

I want a very simple query which finds a user whose mail is 'abc@blah.com'

Following query returns me a null result, I'm not sure what I'm missing here.

Code:

TypedQuery<Users> query = em.createQuery("SELECT u FROM  Users u JOIN u.mail m WHERE m ='abc@blah.com' ", Users.class)
List<Users> users = query.getResultList();

I also tried with adding another embedded object but same result

helpful links:
http://in.relation.to/2015/03/17/hibernate-ogm-times-2413-and-42-beta-1-released/#H-QueryImprovements
http://antoniogoncalves.org/2009/11/01/mapping-and-querying-a-list-of-primitive-types-with-jpa-2-0

Any help would be appreciated

Thanks

Gunnar · **Joined:** Sat Jan 24, 2009 12:46 pm **Posts:** 388

Hi,

Your query is good, it's a bug on our side. I've filed https://hibernate.atlassian.net/browse/OGM-913 for this. Apparently the JOIN syntax for querying element collections currently only works with collections of component types (@Embeddable) but not with collections of primitive types, String etc.

As a workaround, you may either model an @Embeddable representing an e-mail (with a single property for the address) or you refrain to native queries for now (see http://docs.jboss.org/hibernate/stable/ogm/reference/en-US/html_single/#ogm-mongodb-queries-native).

Cheers,

--Gunnar

manaveed · **Joined:** Thu Aug 27, 2015 3:40 pm **Posts:** 2

Thanks Gunnar for your suggestion.

I already did a successful POC of embeddable object with single property when I was looking workaround for this problem.
The thing is we are consuming mongodb collection from third party source and we dont have a control over it.

As a final alternate solution I implement a native query that works for me.

Here is the solution for querying primitive types collection with native query.

Code:

        String strQuery = "{ $query : { 'mail' : 'abc@blah.com'}}";
        Query query = em.createNativeQuery(strQuery, Users.class);
        List<Users> users = query.getResultList();

Chares!
Naveed