CREATE TABLE users (
		user_id Int,
		name 	String,
		age 	Int,
		country String,
		is_active bool
	)
	engine = MergeTree
	order by user_id
	
	insert into mdrozdov.users values
	(1,     'Ivan'	,30,	'RU',	1),
	(2,     'Anna'	,25,	'RU',	1),
	(3,     'Petr'	,45,	'RU',	0),
	(4,     'Olga'	,35,	'RU',	1),
	(5,     'John'	,55,	'US',	1),
	(6,     'Alice'	,42,	'US',	0),
	(7,     'Tom'	,38,	'US',	1),
	(8,     'Lucas'	,28,	'BR',	1),
	(9,     'Maria'	,60,	'BR',	1),
	(10,	'João'	,27,	'BR',	0),
	(11,	'Kenji'	,33,	'JP',	1),
	(12,	'Yuki'	,29,	'JP',	0),
	(13,	'Chen'	,40,	'CN',	1),
	(14,	'Li'	,48,	'CN',	1),
	(15,	'Fatima',31,	'AE',	1),
	(16,	'Ahmed'	,36,	'AE',	1),
	(17,	'George',24,	'US',	1),
	(18,	'Nina'	,34,	'RU',	1),
	(19,	'Max'	,50,	'DE',	1),
	(20,	'Sophie',22,	'DE',	0)
	
	--1. Получи 10 самых старших **активных** пользователей.
	select 
	    user_id,
	    name, 
	    age, 
	    country, 
	    is_active
	from mdrozdov.users
	where is_active
	order by age desc
	limit 10
	--2. Выведи пользователей из `country = 'RU'`, отсортированных по имени.
	select 
	    user_id,
	    name, 
	    age, 
	    country, 
	    is_active
	from mdrozdov.users
	where country = 'RU'
	order by name asc
	--3. Что произойдёт, если написать `LIMIT 10` **без `ORDER BY`**?
	-- ответ будет недетерминирован
	--4. Посчитай количество пользователей по странам.
	select 
	    country,
	    count(user_id) as total_users
	from mdrozdov.users
	group by country
	--5. Для каждой страны выведи минимальный и максимальный возраст.
	select 
	    country,
	    min(age) as min_user_age,
	    max(age) as max_user_age
	from mdrozdov.users
	group by country
	--6. Отсортируй страны по убыванию количества пользователей.
	select 
	    country,
	    count(user_id) as total_users
	from mdrozdov.users
	group by country
	order by total_users desc
	
	-- task 2
	CREATE TABLE mdrozdov.events (
	    user_id Int,
	    event_time DateTime,
	    event_type String --mb better enum but idc
	)
	engine = MergeTree
	order by user_id
	insert into events values
	(1,	'2025-07-17 09:00:00',	'click'),
	(1,	'2025-07-17 09:05:00',	'view'),
	(1,	'2025-07-17 09:10:00',	'purchase'),
	(2,	'2025-07-17 10:00:00',	'click'),
	(2,	'2025-07-17 10:05:00',	'click'),
	(2,	'2025-07-17 11:00:00',	'view'),
	(3,	'2025-07-16 12:00:00',	'view'),
	(3,	'2025-07-16 12:30:00',	'click'),
	(3,	'2025-07-17 08:00:00',	'purchase'),
	(4,	'2025-07-17 13:00:00',	'click'),
	(4,	'2025-07-17 14:00:00',	'view'),
	(4,	'2025-07-17 15:00:00',	'view'),
	(5,	'2025-07-16 20:00:00',	'view'),
	(5,	'2025-07-17 01:00:00',	'click'),
	(5,	'2025-07-17 06:00:00',	'purchase'),
	(6,	'2025-07-17 07:30:00',	'view'),
	(6,	'2025-07-17 08:45:00',	'click'),
	(7,	'2025-07-16 23:59:59',	'click'),
	(7,	'2025-07-17 00:01:00',	'purchase'),
	(7,	'2025-07-17 10:10:00',	'view')
	--1-2) Добавь колонку с кумулятивным количеством событий по user_id (используй count() OVER ...)
	select
	    user_id,
	    event_time,
	    event_type,
	    count(*) over (partition by user_id order by event_time) as total_click_exact_moment,
	    row_number() over (partition by user_id order by event_time) as row_number
	from mdrozdov.events
	--3) да, поддерживается, но не обязательно для коммулятивного суммирования строк
	--4-6) Сделай WITH recent_events AS (...) — все события за последние 24 часа.
	with recent_events AS (
		select *
		from mdrozdov.events
		where event_time >= '2025-07-18'::DATE - interval '1 day'
	), category_list as (
		select 'click' as event_type, 'interaction' as category
		union all
		select 'view', 'interaction'
		union all
		select 'purchase', 'conversion'
	)
	select 
		user_id,
		count(*) as total_events_last_24h,
		count(distinct cl.category) as uniq_categories
	from recent_events re
	left join category_list cl 
		using(event_type)
	group by user_id
	order by total_events_last_24h desc, user_id asc
	limit 5