CODEWITHSUNDEEP
javamongodbmorphia
Silient Killerz
Silient Killerz

Reputation: 58

MongoDB how to load two attributes of reference document using morphia

How to load two attributes of reference document/entity using morphia

I have a Class Person and School like this
person class

@Entity
public class Person {
  @Id private ObjectId id;
  private String name;
  @Embedded private PersonEducation schoolInfo;
}
@Embedded
public class PersonEduction {
  @Reference private School school;
  private String year;
  private String degree;
}


School Class

@Entity
public class School {
   @Id private ObjectId id;
   private String name;
   private String address;
   private String description;
}

How I can get id and and name fields of School in Person class example When i want to person 

Person person = datastore.find(Person.class).field("name").equals("xyz").get();
person.gerSchoolInfo();

Response (Not want all School class fields)

{school:{_id:ObjectId("4fcef3e20364a375e7631fb0"), name:"SchoolA"}, year:"1990", degree:"MBA" }

and If I query school where _id=ObjectId("4fcef3e20364a375e7631fb0"), I get all School fields

{_id:ObjectId("4fcef3e20364a375e7631fb0"), name:"xyz", address="some add", description="some desc"}

Upvotes: 1

Views: 2227

Answers (2)

maaz
maaz

Reputation: 4493

Instead of using @Reference you should use 

key<School> school;

and use custom query to load it.

datastore.createQuery(School.class).retrivedFields(true, "id","name");

Upvotes: 1

Nic Cottrell
Nic Cottrell

Reputation: 9685

To give an alternative to mtariq, replace

@Reference private School school;

with 

private ObjectId schoolId;

and fetch it yourself. However since your School class is so simple I think you'd be better off using Lazy loading, so:

@Reference @Lazy private School school;

This will only load the school object when/if it is referenced.

Upvotes: 0

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