Question

When I am trying to do this

select first_name from employees 
group by salary,first_name
having salary between 0 and 4800

I am getting 49 records

When I am trying to do this I am getting no results

select first_name from employees 
group by salary,first_name
having salary between 0 and (max(salary)/5)

Here select max(salary)/5 from employees fetches : 4800

This is simple but I don’t know what silly mistake I am doing

Answer 1

In this statement

select first_name from employees 
group by salary,first_name
having salary between 0 and (max(salary)/5)

you’re grouping by salary and first_name, which is likely grouping by just one row. You’re essentially looking for X that’s between 0 and X/5, which is likely to return no results.

In this statement

select max(salary)/5 from employees fetches

you’re grouping by nothing, so you get the max salary of everyone.

I think this

select first_name from employees 
WHERE salary between 0 and (SELECT max(salary) FROM employees)/5

is what you’re looking for