java jpa hibernate rollback on onetomany

I have a model formheader for my jpa which i consider the parent

@Entity
@Table(name = "Form_Header")
public class FormHeader {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "header_id", nullable = false)
    private Long headerId;

    @OneToMany(
        mappedBy = "formHeader",
        cascade = CascadeType.ALL,
        orphanRemoval = true
    )
    private List<FormProdItem> formProdItem;

    -- more fields--

    -- getter and setter--

}

and another model which I consider as the child. more on unidirectional

@Entity
@Table(name = "Form_Prod_Item")
public class FormProdItem {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "item_id", nullable = false)
    private Long itemId;

    @Column(name = "header_id", nullable = false)
    private Long headerId;

    @ManyToOne(fetch = FetchType.LAZY)
    private FormHeader formHeader;

   -- more fields --

   -- getter and setter --

}

and my DAO to access the DB

@Repository
@Transactional
public class FormHeaderDAO {

    @Autowired
    private EntityManager entityManager;

    public List<FormHeader> gettest() {
	
        try {
    	
    	    String sql = " SELECT e FROM FromHeader e "
    	    + " WHERE  e.isDeleted = 0 ";
    	
    	    Query query = entityManager.createQuery(sql, FormHeader.class);
    	
        
            return (List<FormHeader>) query.getSingleResult();
        } catch (NoResultException e) {
            return null;
        } catch (Exception e) {
            return null;
        }
    }
}

I'm getting this error without any further details

2020-09-16 09:19:10.324 ERROR 9624 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.transaction.UnexpectedRollbackException: Transaction silently rolled back because it has been marked as rollback-only] with root cause

org.springframework.transaction.UnexpectedRollbackException: Transaction silently rolled back because it has been marked as rollback-only

even if I add in sql "join e.formProdIem f" the error is the same and it wont provide and more details. Any idea why?

My guess is you are getting a NonUniqueResultException because your query returns more than one result and you call query.getSingleResult() but you don't see that because you are catching exceptions and discarding them silently. Which is a really bad idea.

@Slf4j
@Repository
@Transactional
public class FormHeaderDAO {

    @Autowired
    private EntityManager entityManager;

    public List<FormHeader> gettest() {
    
        try {
            String sql = " SELECT e FROM FromHeader e "
            + " WHERE  e.isDeleted = 0 ";
        
            Query query = entityManager.createQuery(sql, FormHeader.class);
        
            return (List<FormHeader>) query.getSingleResult();
        } catch (NoResultException e) {
            log.error(e)
            return null;
        } catch (NonUniqueResultException e) {
            log.error(e)
            return null;
        } catch (Exception e) {
            log.error(e)
            return null;
        }
    }
}

If you don't have Slf4j use System.err.println() or a break point to confirm what kind of exception your code is swallowing right now.