sql 테이블설정

변경 전 SELECT c.title, a.cnt_checkins, b.cnt_total, (a.cnt_checkins/b.cnt_total) AS ratio FROM ( SELECT course_id, count(DISTINCT (user_id)) AS cnt_checkins FROM checkins GROUP BY course_id ) a INNER JOIN ( SELECT course_id, count(*) AS cnt_total FROM orders GROUP BY course_id ) b ON a.course_id = b.course_id INNER JOIN courses c ON a.course_id = c.course_id 변환 하기 변경 후 WITH table1 AS( SELECT cours..