プログラマーとプログラミングに熱心な人々のための質問と回答
DECLARE @tagName NVARCHAR(255) = 'flash' -- TagName: Tag name of the question. DECLARE @beginDate DATETIME = '2010-01-08' DECLARE @endDate DATETIME = '2023-03-01' SELECT T.Month, (T.QuestionCount - T.UnansweredCount) / CAST(T.QuestionCount AS DECIMAL) AS AnswerRate FROM (SELECT CAST( CAST(DATEPART(YEAR, CreationDate) AS NVARCHAR) + '-' + CAST(DATEPART(MONTH, CreationDate) AS NVARCHAR) + '-01' AS DATETIME) AS 'Month', SUM(CAST ( CASE WHEN AnswerCount = 0 THEN 1 ELSE 0 END AS INT)) AS 'UnansweredCount', COUNT(*) AS 'QuestionCount' FROM Posts p INNER JOIN PostTags pt ON p.Id = pt.PostId INNER JOIN Tags t ON t.Id = pt.TagId WHERE (p.PostTypeId = 1) AND (t.TagName = @tagName) AND (p.CreationDate BETWEEN @beginDate AND @endDate) GROUP BY DATEPART(YEAR, CreationDate), DATEPART(MONTH, CreationDate)) T ORDER BY T.Month ASC