Never, Ever, Ever Start T-SQL Comments with Two Dashes

There are two ways you can write comments in T-SQL:

–By starting a line with two dashes, or /* By framing it on both sides like this */

Never, ever use two dashes. Never.

The problem is that monitoring tools and diagnostic management views often dump out the T-SQL in one long line. So this query:

SELECT * FROM dbo.Users WHERE DisplayName = N’Brent Ozar’ — This line is a comment AND Location = N’Iceland’ ORDER BY Reputation DESC;

Becomes this:

SELECT * FROM dbo.Users WHERE DisplayName = N’Brent Ozar’ — This line is a comment AND Location = N’Iceland’ ORDER BY Reputation DESC;