String to ObjectId mapping error when using query method

[grwang91]

Having problem using query method, as query generated by spring-data-mongodb is consist of string type _id, not ObjectId.

@Document("test_entity")
public class TestEntity {
	@MongoId(targetType = FieldType.OBJECT_ID)
	private String id;

	private String testField;
}

public interface TestRepository extends MongoRepository<TestEntity, String> {
	List<TestEntity> findAllByIdGreaterThan(String id);
}

Entity and Repository are declared like above code.

And I tested by below simple test code.

@SpringBootTest
class TestRepositoryTest {

	@Autowired
	private TestRepository testRepository;

	@Test
	void test() {
		TestEntity entity = new TestEntity();
		testRepository.save(entity);

		List<TestEntity> result = testRepository.findAllByIdGreaterThan("000000000000000000000000");
	}
}

It is supposed to return all documents in DB, as "000000000000000000000000" is minimum value of ObjectId. But nothing returned.
Also, It seems Mongotemplate is querying by string type _id.

2023-08-31T22:20:55.784+09:00 DEBUG 72457 --- [    Test worker] o.s.d.m.r.query.MongoQueryCreator        : Created query Query: { "id" : { "$gt" : "000000000000000000000000"}}, Fields: {}, Sort: {}
2023-08-31T22:20:55.789+09:00 DEBUG 72457 --- [    Test worker] o.s.data.mongodb.core.MongoTemplate      : find using query: { "_id" : { "$gt" : "000000000000000000000000"}} fields: Document{{}} for class: class com.example.mongodb_test.entity.TestEntity in collection: test_entity

I could solve this problem with a temporary solution, by using custom @query like below, with appropriate debug log using $oid.

@Query("{'_id': {'$gte': {'$oid': ?0}}}")
	List<TestEntity> findAllByIdGreaterThan(String id);

2023-08-31T22:24:31.959+09:00 DEBUG 72886 --- [    Test worker] o.s.d.m.r.query.StringBasedMongoQuery    : Created query Document{{_id=Document{{$gte=000000000000000000000000}}}} for Document{{}} fields.
2023-08-31T22:24:31.965+09:00 DEBUG 72886 --- [    Test worker] o.s.data.mongodb.core.MongoTemplate      : find using query: { "_id" : { "$gte" : { "$oid" : "000000000000000000000000"}}} fields: Document{{}} for class: class com.example.mongodb_test.entity.TestEntity in collection: test_entity

But still I can't use query method with _id.

Am I using query method in wrong way? or It's id type bug?

[Lucasark]

I dont know if you have any particular reason to use "findAll", but if you call "findByIdGreaterThan" (return Optional) it will do what you describe. Btw, ID's should be unique, so always it will be found 1 or 0, and not a List.

PS.: On your custom query you use GTE and your jpa is on GT.

[grwang91]

I dont know if you have any particular reason to use "findAll", but if you call "findByIdGreaterThan" (return Optional) it will do what you describe. Btw, ID's should be unique, so always it will be found 1 or 0, and not a List.

PS.: On your custom query you use GTE and your jpa is on GT.

I need to use "findAll" by my business logic requirement, so "findByIdGreaterThan" is not appropriate choice. Also, "findByIdGreaterThan" still queries by string type _id.

[Lucasark]

I dont know if you have any particular reason to use "findAll", but if you call "findByIdGreaterThan" (return Optional) it will do what you describe. Btw, ID's should be unique, so always it will be found 1 or 0, and not a List.
PS.: On your custom query you use GTE and your jpa is on GT.

I need to use "findAll" by my business logic requirement, so "findByIdGreaterThan" is not appropriate choice. Also, "findByIdGreaterThan" still queries by string type _id.

Can you describe better your case? Because I can't see where it could be appropriate. I can imagine only one scenario when you have compound id, like:

@Document("test_entity")
public class TestEntity {

	@Id
	private TestId id;

	private String testField;
}



public class TestId{

	private String id1;

	private String id2;
}

Your document will be:

{
_id:{
  id1: "val",
  id2: "val
},
testField: "val"
}

About "findByIdGreaterThan", you should use ObjectId in your method on interface, like
:

Optional<TestEntity> findByIdGreaterThan(ObjectId id);

It will produce same @query that you describe on your custom

[grwang91]

I need to get list of documents greater than certain _id, for pagination. _id is used as cursor, and I need range query.

[Lucasark]

I need to get list of documents greater than certain _id, for pagination. _id is used as cursor, and I need range query.

Now I got it! And I think we had miss conception of "ALL", if you have a look on "findAllById" from JPA it is Iterable, like:

findAllById(List.of(id1, id2, id3..., idN))

So, it will need construct $in, like: { "_id" : { "$in" : [{ "$oid" : "64f17a0ef6bfc9364e25cef7"}]}} , and it will return a List from this id`s

Ok, now move on for what you need, that is a List<> by 1 id (I think is it), for my example, I build two method on interface:

public interface TestRepository extends MongoRepository<TestEntity, String> {
    List<TestEntity> findByIdGreaterThan(String id);
    List<TestEntity> findByIdGreaterThan(ObjectId id);
}

GreatThan does not know your "comparable" otherwise you explicit. So, take my example:

Using both method in order, it will produce from JPA:

findByIdGreaterThan(String id); will return none, like you already said, because in mongodb this is not a String value.
findByIdGreaterThan(ObjectId id) will return one (because I used GT), and now it is explicit that is ObjectId.

Same scenario can be reproduce with other types like: Date, Integer, Geo...

PS.: I can use findAllBy"Something", but it will be same findBy

PS2.: This where you can find when Criteria construct query

org.springframework.data.mongodb.core.query

    public Criteria gt(Object value) {
        this.criteria.put("$gt", value);
        return this;
    }

[grwang91]

It works well if I declare id with ObjectId.
However, I think string type id should work well, as it seems spring data mongodb supports String to ObjectId conversion.

If I use String type id and call testRepository.findById, id field is automatically converted to ObjectId. Also, I can identify query log using $oid, unlike query method.

So I think there's hole regarding id field conversion in query method.

[christophstrobl]

The generated query should take the targetType of @MongoId into account. @grwang91, which version of data-mongodb are you using? Any customisations to the mapping? Ideally please take the time to provide a complete minimal sample (something that we can unzip or git clone, build, and deploy) that reproduces the problem.

[grwang91]

@christophstrobl
I'm using spring-boot-starter-data-mongodb:3.1.3, no customize at mapping.

Here's sample git repository.
https://github.com/grwang91/mongodb_test

[grwang91]

@christophstrobl
If it is a real bug that has to be fixed, can I take a look?

[christophstrobl]

@grwang91 it's on the list of issues to tackle. If you've time to investigate further and propose a solution we'd be happy to review it.

[grwang91]

@christophstrobl
I found the reason and there are two options to solve.

First option is modifying at MongoQueryCreator level. (Submitted PR)
Second option is modifying at QueryMapper level that modifies 'else' branch on below code. (line 496)

As a maintainer, can you advise which option is better?

[christophstrobl]

Thank you for digging into it. The QueryMapper is the place where the conversion should happen.