Using ranking to select the top 10 tuples in Oracle SQL

Question

I have a relationship instructor (ID, name, department name, salary).

The question in our assignment asks us: to use the rank function in SQL to write a query on the identifier and name of those instructors from the top 10 highest paid.

I can rank instructors with select id, name, rank() over(order by(salary) desc) as sal from instructor order by sal

What is my next step in grabbing the top 10 instructors? Thank.

Answer 1

Your solution is close to the answer, but it is usually better to use the value set by the RANK () function:

select id
       , name
       , sal
from (
  select id
        , name
        , sal
        , rank() over(order by(salary) desc) as sal_rank
    from instructor
  )
where sal_rank <=10
/

rownum , . , , . ROWNUM .

ROWNUM - ROW_NUMBER() - . -.

Answer 2

, rownum...

select id, name from(
  select id, name, rank() over(order by(salary) desc) as sal
    from instructor order by sal
  )
where rownum <=10

, - !