Convert Objects from Query to other Class in Hibernate?

Question

I have following problem: I am using Spring + Hibernate and am currently trying to select an id + amount of its id and return a list with each id and its corresponding amount. Now the problem is, that apperently the converter has a problem as I get following exception :

ConverterNotFoundException: No converter found capable of converting from type [java.lang.Long] to type [...entity.E_Amount]] with root cause

E_Amount creates Obejects with an id and an amount. And My Query:

 @Query("select t.e.id, count(t.id) from...")

returns a perfectly fine result of a long and an integer e.g. {9,101}

I am simply not completely sure how to start tackling this converting problem. Any ideas would be greatly appreciated!

Maciej Kowalski · Accepted Answer · 2019-01-09 15:44:02Z

1

Try the result class strategy:

1) Create a new class ResultClass with constructor accepting your query results:

public class ResultClass{

    public ResultClass(Integer id, Long count){..}
}

2) Amend the query a bit:

@Query("select new com.mypackage.ResultClass(t.e.id, count(t.id)) from...")
public List<ResultClass> query(..);

Just make sure that constructor arguments are in the same order as column in the select statement.

answered Jan 9, 2019 at 15:44

Maciej Kowalski

26.7k12 gold badges59 silver badges66 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

FoolischEx Over a year ago

So basically as in my case E_Amount ? I tried it with select new com.*...*.E_Amount(...)) and now I received an IllegalArgumentException.

FoolischEx Over a year ago

Ok so my current problem is that I actually have a spring/hibernate builder class for that object and therefore cant have a standard constructor , i think ? I am new to spring + hibernate so this is kinda confusing me. Anyway , my Server is giving me DetailedSemanticException as it cant locate an appropriate constroctur on class E_Amount ...

Collectives™ on Stack Overflow

Convert Objects from Query to other Class in Hibernate?

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related