Spring JPA DTO Mapping

Here has a good example about it. https://stackoverflow.com/questions/64762080/how-to-map-sql-native-query-result-into-dto-in-spring-jpa-repository A copy was made here just in case it gone. All credit for the below two code sections go to SternK on stackoverflow.

import javax.persistence.NamedNativeQuery;
import javax.persistence.SqlResultSetMapping;
import javax.persistence.ConstructorResult;
import javax.persistence.ColumnResult;

@Entity
@NamedNativeQuery(
    name = "find_stock_akhir_dto",
    query =
        "SELECT " + 
        "  stock_akhir.product_id AS productId, " + 
        "  stock_akhir.product_code AS productCode, " + 
        "  SUM(stock_akhir.qty) as stockAkhir " + 
        "FROM book_stock stock_akhir " + 
        "where warehouse_code = :warehouseCode " + 
        "  AND product_code IN :productCodes " + 
        "GROUP BY product_id, product_code, warehouse_id, warehouse_code",
    resultSetMapping = "stock_akhir_dto"
)
@SqlResultSetMapping(
    name = "stock_akhir_dto",
    classes = @ConstructorResult(
        targetClass = StockAkhirDto.class,
        columns = {
            @ColumnResult(name = "productId", type = Long.class),
            @ColumnResult(name = "productCode", type = String.class),
            @ColumnResult(name = "stockAkhir", type = Integer.class)
        }
    )
)
public class SomeEntity
{
}

@Repository
public interface StockRepository extends RevisionRepository<Stock, Long, Integer>, JpaRepository<Stock, Long> {

   @Query(name = "find_stock_akhir_dto", nativeQuery = true)
   List<StockAkhirDto> findStockAkhirPerProductIn(
      @Param("warehouseCode") String warehouseCode,
      @Param("productCodes") Set<String> productCode
   );
}

Try to set a break point on ConstructorResultColumnProcessor.resolveConstructor, and see the result data column type field by field, and see which one is mismatch.