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

2026-03-18 13:14:45 +03:00
parent 9a3e660595
commit 3b9c6393df
1 changed files with 41 additions and 0 deletions
@@ -0,0 +1,41 @@
 CREATE MATERIALIZED VIEW course_summary AS
 WITH courses_unique_users AS (
 	SELECT
 		e.course_id,
 		count(e.user_id) AS unique_users
 	FROM
 		enrollments e
 	GROUP BY
 		e.course_id
 ),
 lessons_results AS (
 	SELECT
 		l.course_id,
 		count(distinct l.id) AS lessons_count,
 		count(lv.lesson_id) AS total_views,
 		min(lv.viewed_at)::date AS first_viewed_at,
 		max(lv.viewed_at)::date AS last_viewed_at
 	FROM
 		lessons l
 	LEFT JOIN
 		lesson_views lv ON l.id = lv.lesson_id
 	GROUP BY
 		l.course_id
 )
 SELECT
 	c.id AS course_id,
 	c.title AS course_title,
 	cuu.unique_users,
 	lr.lessons_count,
 	lr.total_views,
 	round(lr.total_views / cuu.unique_users::numeric, 2) AS avg_views_per_user,
 	lr.first_viewed_at,
 	lr.last_viewed_at
 FROM
 	courses c
 JOIN	
 	courses_unique_users cuu ON c.id = cuu.course_id
 JOIN
 	lessons_results lr ON c.id = lr.course_id
 ORDER BY
 	c.id;