解答
185
SQL文(クエリ)
WITH master AS ( SELECT cid , session_count , device , MAX(cv_page) AS cv FROM ( SELECT * , IF(page = "/thank_you/", 1, 0) AS cv_page FROM sample.web_log ) GROUP BY cid , session_count , device ) SELECT device , SUM(cv) AS cv , COUNT(*) AS session , round(SUM(cv) / COUNT(*), 4) AS cvr FROM master GROUP BY device