// PL/SQL Basic // Author: Hamed Farvardin // HR DB Oracle Express Version 11.2.0.2.0 // Chapter 8 --- Create view select emp.first_name , emp.last_name , dep.department_name from employees emp , departments dep where emp.department_id = dep.department_id create view emp_info_1 (Name , Family_name , department) as select emp.first_name , emp.last_name , dep.department_name from employees emp , departments dep where emp.department_id = dep.department_id select * from emp_info select * from emp_info_1 drop view emp_info --- set operator -- Union select department_id , department_name from departments where department_id <= 30 union select department_id , department_name from departments where department_id > 20 --- intersect select department_id , department_name from departments where department_id <= 30 intersect select department_id , department_name from departments where department_id > 20 -- Minus select * from departments select department_id , department_name , manager_id from departments where department_id <= 30 minus select department_id , department_name ,111 from departments where department_id > 20 order by department_id asc