Запросы - Синтаксис (Task 1 and 2) v2

dsolovianov/clickhouse/Homework/Запросы - Синтаксис.sql

@@ -2,7 +2,7 @@
 
 --! Задача 1 !--
 
-DROP TABLE IF EXISTS users ON CLUSTER clickhouse_cluster;
+DROP TABLE IF EXISTS dsolovianov.users ON CLUSTER clickhouse_cluster SYNC;
 
 CREATE TABLE users 
 ON CLUSTER clickhouse_cluster 
@@ -11,8 +11,11 @@ ON CLUSTER clickhouse_cluster
     name String,
     age UInt8,
     country String,
-    is_active UInt8
+    is_active Boolean
-) ENGINE = MergeTree()
+) ENGINE = ReplicatedMergeTree(
+    '/clickhouse/tables/{shard}/dsolovianov/users_v2',
+    '{replica}'
+)
 ORDER BY user_id;
 
 INSERT INTO users VALUES
@@ -73,6 +76,12 @@ SELECT
 FROM users
 GROUP BY country;
 
+SELECT 
+    country,
+    uniqExact(country) as unique_countries --возвращает точное количество уникальных значений в столбце country
+FROM users
+GROUP BY country;
+
 --Для каждой страны выведи минимальный и максимальный возраст.
 SELECT 
     country,
@@ -90,6 +99,18 @@ FROM users
 GROUP BY country
 ORDER BY user_country DESC;
 
+--Всё вместе
+SELECT 
+    country,
+    COUNT(*) as user_country,
+    SUM(is_active) as active_users,
+    MIN(age) as min_age,
+    MAX(age) as max_age,
+    uniqExact(country) as unique_countries
+FROM users
+GROUP BY country
+ORDER BY country;
+
 --! Задача 2 !--
 
 DROP TABLE IF EXISTS dsolovianov.events ON CLUSTER clickhouse_cluster SYNC;
@@ -104,7 +125,7 @@ ENGINE = ReplicatedMergeTree(
     '/clickhouse/tables/{shard}/dsolovianov/events_v2',
     '{replica}'
 )
-ORDER BY user_id;
+ORDER BY (user_id, event_time);
 
 INSERT INTO dsolovianov.events (user_id, event_time, event_type) VALUES
 (1, '2025-07-17 09:00:00', 'click'),
@@ -221,4 +242,3 @@ ORDER BY re.user_id, re.event_time;
 многоуровневые CTE - да
 рекурсивные CTE - нет в классическом понимании, а скорее в итеративном смысле.
 */
-