MongoDB如何使用morphia加载参考文档的两个属性

Question

如何使用morphia加载引用文档/实体的两个属性

@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;
}

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

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

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

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

Answer 1

您应该使用@reference，而不是使用

key<School> school;

并使用自定义查询加载它。

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