order by a condition oracle sql

Question

I'm using ORACLE SQL Developer.

I am trying to order by last name. If I have matching last names then I want to order by first name.

here is my code:

....
order by case 
when student_lname= student_lname
then student_fname
else student_lname
end;

but it doesn't return the result I want.

Thanks

Answer 1

只需按以下order by使用两个键：

order by student_lname, student_fname