Работа над ошибками по: 'Типы таблиц', 'View и Distribute движки'.

mnoskov/clickhouse/практика clickhouse/2. Типы данных/practice_data_types.sql

@@ -13,18 +13,24 @@ ENGINE = ReplicatedMergeTree(
 ORDER BY tuple();
 
 SELECT
+	user_id,
+	balance,
+	created_at
+FROM (
+	SELECT
 	user_id,
 	toDecimal64OrNull(balance,2) AS balance,
 	toDateTime64OrNull(created_at, 3) AS created_at
 FROM
 	mnoskov.raw_data1
+)
 WHERE
 	balance IS NOT NULL AND created_at IS NOT NULL;
 
 
 -- Задание 2
 
-CREATE TABLE events 
+CREATE TABLE mnoskov.events 
 ON CLUSTER clickhouse_cluster (
   event_id String,
   event_date String,  -- форматы: "2023-01-01", "01.02.2023", "invalid"
@@ -42,18 +48,16 @@ SELECT * FROM mnoskov.events;
 
 SELECT
 	event_id,
-	toDate(parseDateTimeBestEffortOrNull(event_date)) AS event_dates,
-	CASE
-		WHEN toDayOfMonth(parseDateTimeBestEffortOrNull(event_time)) = 1 THEN toHour(parseDateTimeBestEffortOrNull(event_time))
-		ELSE (toDayOfMonth(parseDateTimeBestEffortOrNull(event_time)) - 1) * 24 + toHour(parseDateTimeBestEffortOrNull(event_time))
-	END AS event_times,
-	toDateTime(parseDateTimeBestEffortOrNull(event_date)) + toIntervalHour(event_times) AS event_datetime
-FROM
-	mnoskov.events
+	event_datetime
+FROM (
+	SELECT
+		event_id,
+		parseDateTimeBestEffortOrNull(concat(event_date, ' ', event_time)) AS event_datetime
+	FROM
+		mnoskov.events
+)
 ORDER BY
-	event_dates;
--- Все преобразования с to... и parse... нашел тут https://clickhouse.com/docs/ru/sql-reference/functions/type-conversion-functions#toIntervalMonth.
--- explain analyze не работает, потэому не могу посмотреть насколько это эффективно, НО главное сам запрос работает.
+	event_datetime;
 
 
 -- Задание 3
@@ -73,7 +77,7 @@ ORDER BY
 
 SELECT
 	user_id,
-	count(*)
+	count(*) as user_actions_cnt
 FROM
 	mnoskov.user_activity
 WHERE