Q&A for professional and enthusiast programmers
SELECT COUNT(DISTINCT p.Id) FROM POSTS p LEFT JOIN Comments c ON p.Id = c.PostId WHERE p.PostTypeId = 1 AND p.AcceptedAnswerId IS NOT NULL AND DATEDIFF(minute, p.CreationDate, c.CreationDate) < 15 AND c.UserId = p.OwnerUserId HAVING COUNT(c.ID) > 0