Q&A for scientists using computers to solve scientific problems
WITH PostingHistory AS (SELECT OwnerUserId FROM Posts WHERE PostTypeId IN (1,2) AND CreationDate > DATEADD(month, -1, GETUTCDATE()) ), Commenting AS (SELECT UserId FROM Comments WHERE CreationDate > DATEADD(month, -1, GETUTCDATE()) ), Editing AS (SELECT UserId FROM PostHistory WHERE PostHistoryTypeId IN (4, 5, 6) AND CreationDate > DATEADD(month, -1, GETUTCDATE()) ) SELECT COUNT(*) FROM Users WHERE Users.Id IN (SELECT OwnerUserId FROM PostingHistory) OR Users.Id IN (SELECT UserId FROM Commenting) OR Users.Id IN (SELECT UserId FROM Editing)