When they ask a question in the exam, how do you know which topic they testing and which method they want you to use to solve the problem.
Example, look at the way question 1 is asked in the practice 6 problem set. In this case you know they testing sub queries because of the chapter the question is part of. But if you take that question as is and put it in the exam, you could potentially have solved it without a sub query.
For example you could have done it like this:
SELECT e.employee_id, e.last_name, e.first_name, e.department_id,
c.employee_id, c.last_name, c.first_name, c.department_id
FROM employees e JOIN employees c
ON (e.employee_id <> c.employee_id)
AND (e.department_id = c.department_id)
WHERE e.last_name = :LastName
ORDER BY e.department_id,e.employee_id,c.employee_id;
[I included all sorts of unnecessary columns just to check if the answer is right]. Assuming the above gives you the same results as the lecturers solution with the sub queries, how do you know which solution to apply in order to comply with the topic being tested in the exam question? Will there always be a hint? Like "Use Sub Queries"? At what point does a HINT become an instruction? What if you ignore the HINT and just do it another way ?
