I am using Azure Cosmos DB for MongoDB. I have two collections: cars and parkings. A car knows what parking it is in via an @DBRef . I have the following document classes
@Document("cars")
data class CarDocument(
@Id
val id: String,
@DBRef
val parking: ParkingDocument?
}
@Document("parkings")
data class ParkingDocument(
@Id
val id: String
}
And the following spring data repositories:
@Repository
interface CarMongoRepository : MongoRepository<CarDocument, String> {
fun findByParkingId(id: String): List<CarDocument>
}
@Repository
interface ParkingMongoRepository : MongoRepository<ParkingDocument, String>
When calling findByParkingId('some existent parking id'), it doesn't return any result because the actual filter that spring data sends to CosmosDB for MongoDB is
{
"parking": {
"$ref": "parkings",
"$id": "some existent parking id"
}
}
I tested this filter in a real MongoDB and it works perfectly: it returns all cars that are parked in that parking. But when running it in CosmosDB for MongoDB, it doesn't match any car. I had to write the filter like this outside of Spring Data (Studio3T) in order to have a match:
{ "parking._id" : "some existent parking id" }
But I can't get Spring Data to build the filter like this. Question: Do you know how to build the filter like this using Spring Data repositories? Or how to make CosmosDB for MongoDB understand the MongoDB's filter?
PS:
I tried to delete the @DBRef annotation, but I don't want to store duplicated parkings, because they are very big entities and it would be a nightmare to manage the integrity. Also there is an index in one of it's fields that would be nested as car.parking.code (which I removed from the previous example code to keep it minimal), which isn't allowed in CosmosDB.
