解答
208
SQL文(クエリ)
WITH ses AS ( SELECT FORMAT_DATETIME("%Y-%m", date_time) AS year_month , COUNT(DISTINCT CONCAT(cid, session_count)) AS session FROM sample.web_log GROUP BY year_month ) , cvs AS ( SELECT year_month , SUM(cv) AS sum_cv FROM ( SELECT FORMAT_DATETIME("%Y-%m", date_time) AS year_month , CONCAT(cid, session_count) AS session , MAX(IF(page = "/thank_you/", 1, 0)) AS cv FROM sample.web_log GROUP BY year_month , session ) GROUP BY year_month ) SELECT CORR(session, sum_cv) AS correlation FROM ( SELECT * FROM ses LEFT JOIN cvs USING (year_month) )