Spring Boot Mongo findById returns null

Question

I have a collection, with documents having a field named _id of type String, not generated manually.

I have been trying to get a document using its id.

    val criteria = Criteria.where("_id").`is`("a2z3e44R")
    val document = mongoTemplate.findOne(Query.query(criteria), MyDocument::class.java) // returns null

    val criteria = Criteria.where("_id").`is`(ObjectId("a2z3e44R"))
    val document = mongoTemplate.findOne(Query.query(criteria), MyDocument::class.java) // returns null

    val document = mongoTemplate.findById("a2z3e44R", MyDocument::class.java) // returns null

    mongoTemplate.findAll(MyDocument::class.java).first { myDocument ->
        myDocument._id == "a2z3e44R"
    } // OK...

MyDocument is

data class MyDocument(val _id: String, val name: String)

Trying to find a document by another field works.

An idea of what I could be missing or a workaround?

Can you please post your JSON document the way you get it through mongo.exe or Robo3T? — dnickless
– dnickless, Commented Oct 9, 2018 at 19:18

Matej Marconak · Accepted Answer · 2018-10-09 15:36:18Z

2

Try mark _id with annotation @Id. The @Id annotation is used to specify the identifier for Spring.

data class MyDocument(@Id val _id: String, val name: String)

answered Oct 9, 2018 at 15:36

Matej Marconak

1,4133 gold badges21 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Tristan Over a year ago

I implemented your suggestion using import org.springframework.data.annotation.Id but the result remains the same.

Matej Marconak Over a year ago

How do you persist new data?

Tristan Over a year ago

It is another program taking care of adding data. I am only reading them.

lczapski · Accepted Answer · 2019-12-24 08:13:26Z

2

You should indicate the type of the id like this

public class Article {

    @MongoId(value = FieldType.OBJECT_ID)
    private String id;

    private String title;

    private String desc;
}

edited Dec 24, 2019 at 8:13

lczapski

4,1603 gold badges18 silver badges35 bronze badges

answered Dec 24, 2019 at 7:53

guodong508

212 bronze badges

1 Comment

Nestor Milyaev Over a year ago

That is a winner answer

Fernix · Accepted Answer · 2018-10-09 15:55:35Z

0

Ypu could define in your repository:

public interface MyDocumentRepository extends MongoRepository<MyDocument, String> {
  Pets findBy_id(ObjectId _id);
}

and use it :

myDocumentRepository.findBy_id("a2z3e44R");

for more info see

or

ObjectId objID = new ObjectId("a2z3e44R");
      query.addCriteria(Criteria.where("_id").lt(objID));

like this other answer link

answered Oct 9, 2018 at 15:55

Fernix

3713 silver badges10 bronze badges

1 Comment

Tristan Over a year ago

This solution is not working either. This was my initial code.

Collectives™ on Stack Overflow

Spring Boot Mongo findById returns null

3 Answers 3

3 Comments

1 Comment

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related