Object Oriented Database Oracle PLSQL

SQL>
SQL>  create type employee_type as object (
  2      employee_id       number,
  3      first_name        varchar2(30),
  4      last_name         varchar2(30)
  5    );
  6    /
Type created.
SQL>
SQL>  create type employee_list_type as varray(50) of employee_type
  2    /
Type created.
SQL>
SQL>
SQL>  create table departments (
  2      department_id   number,
  3      department_name varchar2(30),
  4      manager         employee_type,
  5      employees       employee_list_type )
  6    /
Table created.
SQL>
SQL>
SQL>
SQL> drop table departments;
Table dropped.
SQL> drop type employee_list_type;
Type dropped.
SQL> drop type employee_type;
Type dropped.
SQL>