JPA Entity class which is not mapped to any table - spring-boot

Question

I am using a entity class for mixing two/three table columns in one entity to hold an outcome of SYS_REFCURSOR in oracle
This allows me to have single class which is not mapped to any table but it still is an Entity
#Data
#Entity
#NoArgsConstructor
class EmployeeDetails {
#Id
#Column("emp_id")
String empId;
#Column("job_name")
String jobName;
#Column("dept_name")
String deptName;
//Future requirement
//String updatedBy
}
Now I have an additional requirement, to add who last modified the employee table, I don't want modify the procedure now, the procedure is being re-used in another background procedure and batch jobs.
My question is, is it possible to use #ManyToOne on this class which is obviously not mapped to any table
If not how do avoid manually looping a child array list, is there a ready made option in JPA or spring boot to achieve that.
Or what will be the smartest/recommended way to bring the below Entity into this class
#Data
#Entity
#NoArgsConstructor
#Table(name="app_users")
class AppUsers {
#Id
#Column(name="user_id")
String userId;
#Column
String userName;
}

Answer 1

#Transient, check how this annotation works it will resolve the issue, you need to understand working of #Transient

Answer 2

My spring boot 2.6.2 EntityManager code is as follows
q = em.createStoredProcedureQuery("MY_PROC",EmployeeDetails.class);
q.registerStoredProcedureParameter("OUT_REFC", void.class, ParameterMode.REF_CURSOR);
q.execute();
q.getResultList()
I have modified my class EmployeeDetails as below
#Data
#Entity
#NoArgsConstructor
class EmployeeDetails {
#Id
#Column("emp_id")
String empId;
#Column("job_name")
String jobName;
#Column("dept_name")
String deptName;
#OneToOne
#JoinColumn(
name="user_id",
referencedColumnName="emp_id",
insertable=false,
updatable=false,
nullable=true
)
AppUsers updatedBy;
}
The log prints Hibernate two times one after one as below, first it calls the proc and then it calls the select query, so, I did not wrote that SQL myself, the JPA layer is taking care of it
Hibernate:
{call MY_PROC(?)}
Hibernate:
select
...
...
from app_users
where user_id=?
so, my expectation achieved and I am getting the values