PET project task 3 completed

aharlamcev/postgresql/Pet-projectsql.sql

@@ -272,4 +272,22 @@ create materialized view course_summary AS
 	order by course_id
 ;
 
+--------------------------------------------------------------------------------------------------
+-- 3 задание Общая отчетность по взаимодействию
+create materialized view platform_summary as  
+with total_counts as (
+					select COUNT(id) as total_users,
+					(select COUNT(id) from courses) as total_courses,
+					(select COUNT(id) from lessons) as total_lessons,
+					(select COUNT(id) from lesson_views) as total_views,
+					(select COUNT(distinct user_id) from lesson_views) as users_with_views
+					from users
+					)
+SELECT total_users, total_courses, total_lessons, users_with_views,
+ROUND(1.00 * total_lessons / total_courses, 2) as avg_lessons_per_course,
+ROUND(1.00 * total_views / total_lessons, 2) as avg_views_per_lesson
+from total_counts
+;
+
+