Question

Is the following acceptable in SQL:

SELECT P.pid P.cnt
FROM Professors P
WHERE P.cnt <= Max(SELECT P2.cnt FROM Professors P2)

I am asking because this is provided as an answer to a problem in a midterm by the professor. I have actually tried it in SQL and wasn’t allowed, but I just wanted to make sure.

Answer 1

Syntactically, I would have written it like this:

SELECT P.pid, P.cnt
  FROM Professors P
  WHERE P.cnt <= (SELECT MAX(P2.cnt) FROM Professors P2)

Logically, it doesn’t really seem to accomplish much since the condition will always be true.