Beginner SQL section: avoiding repeated expression

Question

I\'m entirely new at SQL, but let\'s say that on the StackExchange Data Explorer, I just want to list the top 15 users by reputation, and I wrote something like this:

Answer 1

There are good answers for the technical problem already, so I'll only address some of the rest of your questions.

If you're just working with the DataExplorer, you'll want to familiarize yourself with SQL Server syntax since that's what it's running. The best place to find that, of course, is MSDN's reference.

Yes, there are different variations in SQL syntax. For example, the TOP clause in the query you gave is SQL Server specific; in MySQL you'd use the LIMIT clause instead (and these keywords don't necessarily appear in the same spot in the query!).