Azamat
69 lines
2.5 KiB
SQL
69 lines
2.5 KiB
SQL
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CREATE MATERIALIZED VIEW user_activity_summary AS
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SELECT
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u.id AS user_id, -- user_id
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u.name, -- name
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COUNT(DISTINCT e.course_id) AS enrollment_count, -- кол-во записей на курсы
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COUNT(DISTINCT lv.lesson_id) AS viewed_lessons_count, -- кол-во просмотренных уроков
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MAX(lv.viewed_at) AS last_viewed, -- последний просмотр
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MIN(lv.viewed_at) AS first_viewed, -- первый просмотр
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ROUND(COUNT(DISTINCT l.course_id) * 100.0 / COUNT(DISTINCT l.id), 2) || '%' AS engagement_rate -- вовлеченность(процент просмотренных/записанным)
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FROM amaksatov.users u -- основная таблица
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JOIN enrollments e ON e.user_id = u.id -- связь users с enrollments
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LEFT JOIN lesson_views lv ON lv.user_id = e.user_id -- связь lessons с lesson_views
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JOIN lessons l ON l.course_id = e.course_id -- связь уроков с курсами пользователя
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GROUP BY u.id, u.name -- группировка по user_id и name
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ORDER BY user_id; -- сортировка по user_id
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CREATE MATERIALIZED VIEW course_summary AS
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SELECT
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c.id AS course_id,
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c.title AS course_title,
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COUNT(DISTINCT e.user_id) AS unique_users,
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COUNT(DISTINCT l.id) AS lessons_count,
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COUNT(DISTINCT lv.id) AS total_views,
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ROUND(
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CASE
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WHEN COUNT(DISTINCT e.user_id) = 0 THEN NULL
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ELSE COUNT(DISTINCT lv.id) * 1.0 / COUNT(DISTINCT e.user_id)
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END, 2) AS avg_views_per_user,
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MIN(lv.viewed_at) AS first_viewed_at,
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MAX(lv.viewed_at) AS last_viewed_at
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FROM courses c
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LEFT JOIN enrollments e ON e.course_id = c.id
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LEFT JOIN lessons l ON c.id = l.course_id
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LEFT JOIN lesson_views lv ON lv.lesson_id = l.id
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GROUP BY c.id;
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CREATE MATERIALIZED VIEW platform_summary AS
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WITH
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user_stats AS (
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SELECT COUNT(*) AS total_users FROM users
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),
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course_stats AS (
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SELECT COUNT(*) AS total_courses FROM courses
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),
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lesson_stats AS (
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SELECT COUNT(*) AS total_lessons FROM lessons
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),
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view_stats AS (
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SELECT COUNT(*) AS total_views, COUNT(DISTINCT user_id) AS users_with_views
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FROM lesson_views
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)
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SELECT
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u.total_users,
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c.total_courses,
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l.total_lessons,
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v.users_with_views,
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ROUND(l.total_lessons::decimal / NULLIF(c.total_courses, 0), 2) AS avg_lessons_per_course,
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ROUND(v.total_views::decimal / NULLIF(l.total_lessons, 0), 2) AS avg_views_per_lesson
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FROM user_stats u, course_stats c, lesson_stats l, view_stats v;
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