Spring JPA -> Map a ResultSet to a non-existing entity

Question

I need to map the return of a native query to an object

Here is my native query

@Query(value = "select collector from relation;", nativeQuery = true)
     Stream<RelationStatistics> findRelationsStatistics();

Here is my object

 public class RelationStatistics {
     private String collector;
     public RelationStatistics(String collector) {
         this.collector = collector;
     }
     public String getCollector() {
         return collector;
     }
     public void setCollector(String collector) {
         this.collector = collector;
     }
 }

Here is my test

    @Test
    public void test() {
        Stream<RelationStatistics> test = relations.findRelationsStatistics();
        test.forEach(item -> System.out.println(item));
    }

This test return me :

    org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [org.springframework.data.jpa.repository.query.AbstractJpaQuery$TupleConverter$TupleBackedMap] to type [RelationStatistics]

This is an example with only one string attribut but the original native query is a big request so creating an entity will be too difficult.

I have find SqlResultSetMapping but I don't really understand how to use it properly

If someone have an idea of what its possible to do 0_o

maybe this helps... https://stackoverflow.com/questions/42207916/jpa-hibernate-how-can-query-return-non-entities-objects-or-list-of-objects-wit — Ramon jansen gomez, Feb 03 '20 at 16:43
Why native Query, in a JPA-Query you get the Mapping for free. try 'select r from RelationStatistcs r' and native=false — Turo, Feb 03 '20 at 17:19
Not really, i can't add table relations because there is too much relations and this exemple may not work :c — Steven Douillet, Feb 04 '20 at 08:37

score 0 · Accepted Answer · answered Feb 04 '20 at 10:22

0

I found a solution here : JPA : How to convert a native query result set to POJO class collection

Using projection with an interface as an object with getCollector() method and map with this

answered Feb 04 '20 at 10:22

Steven Douillet

5
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Spring JPA -> Map a ResultSet to a non-existing entity

1 Answers1