homework/mnoskov/clickhouse/Практика clickhouse/2. Запросы/1. Синтаксис/practice_syntax.sql

-- Задание 1
CREATE TABLE mnoskov.users
ON CLUSTER clickhouse_cluster
(
	user_id UInt32,
	name String,
	age UInt8,
	country String,
	is_active Bool
)
ENGINE = ReplicatedMergeTree(
    '/clickhouse/tables/{shard}/mnoskov/users',
    '{replica}'
)
ORDER BY user_id;

INSERT INTO mnoskov.users
(user_id,name,age,country,is_active)
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,'Joao',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);

SELECT * FROM mnoskov.users;

--1
SELECT
	user_id,
	age,
	is_active
FROM
	mnoskov.users
WHERE
	is_active = TRUE
ORDER BY
	age DESC
LIMIT 10;

--2
SELECT
	name,
	country
FROM
	mnoskov.users
WHERE
	country = 'RU'
ORDER BY
	name;

--3
SELECT
	user_id,
	age,
	is_active
FROM
	mnoskov.users
WHERE
	is_active = TRUE
LIMIT 10;
-- Данные вывелить так как лежат на диске.

--4
SELECT
	country,
	count() as cnt_users
FROM
	mnoskov.users
GROUP BY
	country;

--5
SELECT
	country,
	min(age) AS min_age,
	max(age) AS max_age
FROM
	mnoskov.users
GROUP BY
	country;

--6
SELECT
	country,
	count() AS cnt_users
FROM
	mnoskov.users
GROUP BY
	country
ORDER BY
	cnt_users DESC;

--Доп
SELECT
	uniqExact(country),
	uniq(country)
FROM
	mnoskov.users;
-- uniqExact(country) - кол-во уникальных значений в колонке country. Но uniq работает также.
-- В инете написано что uniq быстрее.


-- Задание 2
CREATE TABLE mnoskov.events1
ON CLUSTER clickhouse_cluster
(
	user_id UInt32,
	event_time DateTime,
	event_type String
)
ENGINE = ReplicatedMergeTree(
    '/clickhouse/tables/{shard}/mnoskov/events1',
    '{replica}'
)
ORDER BY(user_id,event_time);

INSERT INTO mnoskov.events1
(user_id,event_time,event_type)
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');

SELECT * FROM mnoskov.events1;

--1
SELECT
	user_id,
	event_time,
	event_type,
	count() OVER(PARTITION BY user_id ORDER BY event_time) AS com_users
FROM
	mnoskov.events1;

--2
SELECT
	user_id,
	event_time,
	event_type,
	row_number() OVER (PARTITION BY user_id ORDER BY event_time) rn,
	dense_rank() OVER (PARTITION BY user_id ORDER BY event_time) dr,
	count() OVER(PARTITION BY user_id ORDER BY event_time) AS c,
	sum(1) OVER(PARTITION BY user_id ORDER BY event_time) AS s
FROM
	mnoskov.events1;

--3
SELECT
	user_id,
	event_time,
	event_type,
	count() OVER(PARTITION BY user_id ORDER BY event_time ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS com_users,
	count() OVER(PARTITION BY user_id ORDER BY event_time ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS com_users2
FROM
	mnoskov.events1;
-- все четенько работает, никаких ошибкок нет

--4-5-6
WITH recent_events AS (
	SELECT
		user_id,
		event_time,
		event_type
	FROM
		mnoskov.events1
	WHERE
		event_time < now() - INTERVAL 1 DAY
)
SELECT
	user_id,
	count(*) AS cnt_user_actions
FROM
	recent_events
GROUP BY
	user_id
ORDER BY
	cnt_user_actions DESC
LIMIT
	5;
-- не понял, как сделать 6 пункт.

-- Ответ на вопрос - ну да - поддерживает.