현이 발자취
select last_name || job_id as "Employees" from employees;
select last_name as name, commission_pct comm from employees;
select last_name, job_id, salary, commission_pct from employees
select last_name, salary, 12*(salary+100) from employees;
select last_name, salary, 12*salary+100 from employees;
select last_name, salary, salary+300 from employees;
select department_id, location_id from departments;
select * from departments;
