instruction: SO - Total Posts by Database Server Per Month - SQL Server.
response: SELECT CONCAT(YEAR(P.CreationDate), '-', MONTH(P.CreationDate)) AS YearMonth, 'SQLServer' AS TagName, COUNT(*) AS PostCount FROM Posts AS P INNER JOIN PostTags AS PT ON (P.Id = PT.PostId) INNER JOIN Tags AS T ON (PT.TagId = T.Id) WHERE T.TagName LIKE 'sql-server%' GROUP BY YEAR(P.CreationDate), MONTH(P.CreationDate) ORDER BY YEAR(P.CreationDate) DESC, MONTH(P.CreationDate) DESC