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Fetch selected columns from two or more table using Spring Jpa

@Entity
public class A
//some properties



@Entity
public class B
//Some properties



I want to fetch selected columns from two tables using JPA, I know how to fetch single Entity table data through Repository and Controllers.

Repository:

public interface extends JPARepository<A, Long>
List<A> findAll();


Controller:

public class class_name
@AutoWired
private JPARepository repo;
@RequestMapping("/data")
public List<A> getData()
return repo.findAll();




Above code is to fetch single table data. Now, I want to fetch selected columns from both the tables.

Note: A, B Entities have mappings


1 Answer
1

What you can do is to use @Query annotation on one of your methods in the repository and performs something like this:

public Name
String firstName;
String telephone;

public Name(String firstName,String telephon)
//initialize fields



@Query(select new dummy.Name(u.name,c.telephone) from User u join fetch u.contact c where u.externalId= ?1 )
public Name getName(String externalId)


You can return easily List instead of using constructor query , but i find it cleaner this way.

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