Q&A for pro webmasters
SELECT Users.Id AS [User Link] , Users.CreationDate , Users.LastAccessDate , b.num_badges FROM Users LEFT JOIN ( SELECT UserId, COUNT(DISTINCT Name) num_badges FROM Badges WHERE Name IN ( 'Civic Duty', 'Cleanup', 'Deputy', 'Electorate', 'Marshal', 'Reviewer', 'Sportsmanship', 'Steward' ) GROUP BY UserId) b ON Users.Id = b.UserId