text: create or replace view v_employee_on_dep90 as
  select empl.EMPLOYEE_ID,
         empl.FIRST_NAME,
         empl.LAST_NAME,
         empl.email,
         empl.phone_number,
         empl.hire_date,
         empl.salary,
         coalesce(empl.commission_pct, 0) commission,
         empl.manager_id,
         job.job_id,
         job.job_title,
         job.min_salary as                job_min_salary,
         job.max_salary as                job_max_salary
  from EMPLOYEES empl
           left join JOBS job on empl.JOB_ID = job.JOB_ID
  where empl.DEPARTMENT_ID = 90;
  
  select *
  from USER_VIEWS;
  
  select EMPLOYEE_ID, salary * commission as komisi
  from v_employee_on_dep90;
  
  update v_employee_on_dep90
  set commission = 0.1
  where EMPLOYEE_ID = 100;
  
  create or replace view v_simple_empl_on_dep90 as
  select *
  from EMPLOYEES
  where DEPARTMENT_ID = 90
  with read only constraint ro_simple_empl_dep90;
  
  update v_simple_empl_on_dep90
  set commission_pct = null
  where EMPLOYEE_ID = 100;
  
  select *
  from EMPLOYEES
  where EMPLOYEE_ID = 100;
  
  drop view v_employee_on_dep90 CASCADE CONSTRAINTS;
  
  select * from RECYCLEBIN;
  