Full pet-project

2026-01-11 18:47:48 +06:00
parent 049de3c93a
commit ebe1f00716
1 changed files with 52 additions and 0 deletions
@@ -14,3 +14,55 @@ LEFT JOIN lesson_views lv ON lv.user_id = e.user_id -- связь lessons с les
 JOIN lessons l ON l.course_id = e.course_id  -- связь уроков с курсами пользователя
 GROUP BY u.id, u.name -- группировка по user_id и name
 ORDER BY user_id; -- сортировка по user_id
 CREATE MATERIALIZED VIEW course_summary AS
 SELECT
    c.id AS course_id,
    c.title AS course_title,
    COUNT(DISTINCT e.user_id) AS unique_users,
    COUNT(DISTINCT l.id) AS lessons_count,
    COUNT(DISTINCT lv.id) AS total_views,
    ROUND(
        CASE
            WHEN COUNT(DISTINCT e.user_id) = 0 THEN NULL
            ELSE COUNT(DISTINCT lv.id) * 1.0 / COUNT(DISTINCT e.user_id)
        END, 2) AS avg_views_per_user,
    MIN(lv.viewed_at) AS first_viewed_at,
    MAX(lv.viewed_at) AS last_viewed_at
 FROM courses c
 LEFT JOIN enrollments e ON e.course_id = c.id
 LEFT JOIN lessons l ON c.id = l.course_id
 LEFT JOIN lesson_views lv ON lv.lesson_id = l.id
 GROUP BY c.id;
 CREATE MATERIALIZED VIEW platform_summary AS
 WITH
 user_stats AS (
    SELECT COUNT(*) AS total_users FROM users
 ),
 course_stats AS (
    SELECT COUNT(*) AS total_courses FROM courses
 ),
 lesson_stats AS (
    SELECT COUNT(*) AS total_lessons FROM lessons
 ),
 view_stats AS (
    SELECT COUNT(*) AS total_views, COUNT(DISTINCT user_id) AS users_with_views
    FROM lesson_views
 )
 SELECT
    u.total_users,
    c.total_courses,
    l.total_lessons,
    v.users_with_views,
    ROUND(l.total_lessons::decimal / NULLIF(c.total_courses, 0), 2) AS avg_lessons_per_course,
    ROUND(v.total_views::decimal / NULLIF(l.total_lessons, 0), 2) AS avg_views_per_lesson
 FROM user_stats u, course_stats c, lesson_stats l, view_stats v;