витрина 'Популярность курсов' для 'Пет-проект: Онлайн-курсы'

2026-03-21 20:49:34 +03:00
parent 3e09a2cbc7
commit f7e6b757df
1 changed files with 39 additions and 0 deletions
@@ -0,0 +1,39 @@
 CREATE MATERIALIZED VIEW lesson_popularity_ranking as
 WITH lesson_views_results AS (
 	SELECT
 		lv.lesson_id,
 		count(lv.user_id) AS total_views,
 		count(DISTINCT lv.user_id) AS unique_viewers
 	FROM
 		lesson_views lv
 	GROUP BY
 		lv.lesson_id
 ),
 enrollments_results AS (
 	SELECT
 		e.course_id,
 		count(e.user_id) AS enrolled_to_course
 	FROM
 		enrollments e
 	GROUP BY
 		e.course_id
 )
 SELECT
 	l.id AS lesson_id,
 	l.title AS lesson_title,
 	c.title AS course_title,
 	lvr.total_views,
 	lvr.unique_viewers,
 	round(lvr.total_views / lvr.unique_viewers::numeric, 2) AS avg_views_per_viewer,
 	dense_rank() OVER (ORDER BY lvr.total_views desc) AS popularity_rank,
 	round((lvr.unique_viewers / er.enrolled_to_course::numeric) * 100, 0) || '%' AS completion_rate
 FROM
 	lessons l
 JOIN
 	courses c ON l.course_id = c.id
 JOIN
 	lesson_views_results lvr ON l.id = lvr.lesson_id
 JOIN
 	enrollments_results er ON c.id = er.course_id
 ORDER BY
 	popularity_rank;