rhydian (1/20/2014)
Surely the following is an easier way to accomplish this...SELECT PR.id, PR.ProfessorName, ClassName, ClassYear, ClassSemester
FROM Professor PR
LEFT JOIN
(
SELECT ProfessorID, ClassName, ClassYear, ClassSemester
FROM Class
WHERE ClassYear>=2011
) SQ ON SQ.ProfessorID = PR.Id
WHERE PR.HasTenure = 1
It is equivalent (probably even for performance) to the proposed solution, but 2 SELECTs add visual clutter, IMO: you are repeating the list of fields 2 times. And, in complex queries, you could be tempted to use *, God forbid 😉
For many people, your solution could probably be easier to understand, which has value.
I would prefer to work with people that understands (and writes) the proposed solution, instead of this one.