Situation: I have collection with documents, each document contains such fields: \"_id\"(ObjectId), \"userId\"(String), but it also can be field \"files\"(Object).
When
Another possibility is to use org.springframework.data.mongodb.repository.Query annotation on your method (useful when using MongoRepository):
org.springframework.data.mongodb.repository.Query
MongoRepository
@Query(value="{ files : { $exists : true } }")