ReactiveCrudRepository function returning Tuple

[hfhbd]

Hey,

having an entity class and an entity interface extending ReactiveCrudRepository, please add the possibility to return a tuple from a query instead the entity.

@Table
data class Entity(@Id val id: Int? = null, val cell: String)

interface EntityRepo: ReactiveCrudRepository<Entity, Int> {

    @Query("Select 1, 2")
    fun failing(): Mono<Tuple2<Int, Int>>
}

Currently, the SimpleR2dbcRepository tries to return an Entity instead a Tuple2, which results in failure, because the values does not match the Entity constructor.

Maybe adding the Tuple classes as a codec could be enough.

[ultranav]

I'm having a similar issue where I try to get the count.

[mp911de]

Returning a primitive value works already:

@Query("SELECT COUNT(*) …")
Mono<Integer> getCount();

[ultranav]

For me, the use case is around getting multiple counts.
For instance, I have a query -

SELECT first_name, last_name, age, count(*) from persons WHERE age  < 42 group by age

Is it possible to map the results as Flux<Tuple2<Person, Long>>?

Person:

class Person {
  String firstName;
  String lastName;
  String age;
//other fields
//getters and setters
}

[marioburatto]

Hello @navagator-blue, not sure if you still facing the issue you reported, but it looks like what you really need is a Person's Projection. So this would probably fix your problems:

class PersonByAgeProjection{
    String age;
    Long total;
}

@Repository
public interface PersonRepository extends ReactiveCrudRepository<Person, Integer> {
    @Query("SELECT age, count(*) as total from persons WHERE age  < 42 group by age ")
    Flux<PersonByAgeProjection> listPersonsByAge();
}

Please let me know if it helps.