Creating Entities for this data model

Question

Hi guys,
I have these 3 tables:
create table employee_a
( employee_id int not null primary key ,
  first_name varchar(50) not null ,
  last_name varchar(50) not null )
create table manager_b
( id int not null primary key ,
  manager_employee_id int not null foreign key references employee_a(employee_id) ,
  subordinate_employee_id int not null foreign key references employee_a(employee_id) )
create table user_c
( user_id varchar(20) not null primary key ,
  user_password varchar(100) not null ,
  employee_id int null foreign key references employee_a(employee_id) )* All the employees are defined in employee_a table.
* If an employee is also a manager then its defined in manager_b table. That employee's id is defined in manager_employee_id column while his/her's subordinates employee ids are defined in subordinate_employee_id column.
* All the users of the system are defined in user_c table. If user of the system is also an employee then its defined in employee_id column of user_c table. If user of the system is not an employee then employee_id column is blank of user_c table.
The data may be like this:
insert into employee_a values (1, 'Mark', 'Benson')
insert into employee_a values (2, 'Joe', 'Young')
insert into employee_a values (3, 'Robert', 'Carbone')
insert into employee_a values (4, 'Wendy', 'Swistenenko')
insert into employee_a values (5, 'Tony', 'Lapolla')
-- Joe Young is manager of "Robert Carbone" and "Tony Lapolla"
insert into manager_b values (100, 2, 3)
insert into manager_b values (101, 2, 5)
-- Wendy Swistenenko is manager of "Mark Benson"
insert into manager_b values (102, 4, 1)
-- Users of the system who are also employees
insert into user_c values ('bensonM', 'password', 1)
insert into user_c values ('youngJ', 'test', 2)
-- A user of the system who is not an employee
insert into user_c values ('guest', 'pretty', null)My question is how to define Entities for these 3 tables for JPA. I am concerned about Inheritence Strategy to use.
Thanks

Answer 1

sorry, i couldnt understand your query..
thanks,
baskar.l