referencing a MongoDB collection using @DBRef annotation inside a list of custom object(DTO) but refence value coming as null

Question

I have a model class

AssessmentTemplate

which is like this.

public class AssessmentTemplate {

@Field("_id")
@Id
private String assessmentId;
private Date creationDate;
private String type;
private String status;
@Field("coreQuestions")
private QuestionTemplate[] coreQuestions;
@Field("baseQuestions")
private QuestionsTemplate[] baseQuestions;
}

This is having a nested array of object of

QuestionsTemplate which is like this

public class QuestionsTemplate {
@DBRef
private Question questionsId;
private int score;
}

question

public class Question {
@Id
private String id;
private String name;
@DBRef
private List<Option> options;

}

On querying question, option reference data is getting loaded fine

On Mongo Side-I have a collection of question and assessment template.

While querying data for assessment I am not getting data of question in JSON

need inputs where I might be going wrong. Do request if any more information is needed.

Disclaimer-data added in mongo is through manual JSON input and not through REST endpoint.

score 0 · Accepted Answer · answered Mar 11 '23 at 20:46

the issue was not at the java end but on the mongo-end. the place where I was referencing to question collection I was passing id as

"question":{
"$ref":"question",
"$id":"640b87a5dd7cbc1dac84d65a"
}

instead of that what worked for me is

"question": {
"$ref": "question",
"$id": {
"$oid": "640b87a5dd7cbc1dac84d65a"
}
}

referencing a MongoDB collection using @DBRef annotation inside a list of custom object(DTO) but refence value coming as null

1 Answers1