public interface UserRepository extends JpaRepository<User, Long> {
@Query(value = "SELECT * FROM USERS WHERE EMAIL_ADDRESS = ?0", nativeQuery = true)
User findByEmailAddress(String emailAddress);
}
Let's say I have the code above where I select * from user. What should I do if I don't want this method to return User object. Is there a way I can manually map the data to a custom object MyUser? Can I do all this in the UserRepository interface?
Thanks!
You can do something like this
@Query(value = "SELECT YOUR Column1, ColumnN FROM USERS WHERE EMAIL_ADDRESS = ?0", nativeQuery = true)
List<Object[]> findByEmailAddress(String emailAddress);
You have to do the mapping. Take a look at the Spring Data Repository as well. Source
What about interface based projection?
Basically you write interface with getters that correspond to SQL query parameters.
In this way you even don't need to force @Id parameter on projection:
@Entity
public class Book {
@Id
private Long id;
private String title;
private LocalDate published;
}
public interface BookReportItem {
int getYear();
int getMonth();
long getCount();
}
public interface BookRepository extends Repository<Book, Long> {
@Query(value = "select " +
" year(b.published) as year," +
" month(b.published) as month," +
" count(b) as count," +
" from Book b" +
" group by year(b.published), month(b.published)")
List<BookReportItem> getPerMonthReport();
}
It uses org.springframework.data.jpa.repository.query.AbstractJpaQuery$TupleConverter$TupleBackedMap underneath as proxy for interface in current Spring implementation.
It works for nativeQuery = true too.
select new full.path.to.Constructor(args, go, here) from ... JPA/Hibernate syntax to provide actual constructor type, but not for native queries (( For native queries I use BeanPropertyRowMapper.
