ClickHouse / ClickHouse/clickhouse-cpp

Strange behavior with dateTime

Offen
#398 1 Kommentar 0 Reaktionen 0 zugewiesene Personen Auf GitHub ansehen
documentation enhancement
Vorherrschende Sprache
C
Sterne
382
Forks
209
Ø Merge
1 T. 22 Std.
Gemergte PRs (30 T.)
13

Beschreibung

I modified example

```
inline void DateTime64Example(Client& client) {
Block b;

/// Create a table.
client.Execute("CREATE TABLE IF NOT EXISTS test_datetime64 (dt64 DateTime64(6) primary key)");

std::cerr << std::endl;
{
Query query("insert into test_datetime64 values('2024-10-10 11:00:00')");
client.Execute(query);
}
{
Query query("insert into test_datetime64 FORMAT TSV \n2024-10-10 11:01:00");
client.Execute(query);
}
auto d = std::make_shared(6);
std::time_t tt = std::time(nullptr);
std::cerr << "inserted local time: " << std::asctime(std::localtime(&tt));
std::cerr << "inserted utc: " << std::asctime(std::gmtime(&tt));
d->Append(tt * (int64_t)1000000 + 123456);

b.AppendColumn("dt64", d);
client.Insert("test_datetime64", b);

client.Select("SELECT dt64 FROM test_datetime64 format tsv", [](const Block& block)
{
for (size_t c = 0; c < block.GetRowCount(); ++c) {
auto col = block[0]->As();
uint64_t t = col->As()->At(c);

std::time_t ct = t / 1000000;
uint64_t us = t % 1000000;
std::cerr << "selected local time: " << std::asctime(std::localtime(&ct));
std::cerr << "selected utc time: " << std::asctime(std::gmtime(&ct));
std::cerr << "us: " << us << std::endl;
}
}
);

/// Delete table.
// client.Execute("DROP TEMPORARY TABLE test_datetime64");
}
```

The server was run with time zone Asia/Tokyo.
The test program I run twice in two different time zones Europe/Paris Europe/Moscow and has the results of insert:

selected local time: Thu Oct 10 05:00:00 2024
selected utc time: Thu Oct 10 02:00:00 2024
us: 0
selected local time: Thu Oct 10 05:00:00 2024
selected utc time: Thu Oct 10 02:00:00 2024
us: 0
selected local time: Thu Oct 10 05:01:00 2024
selected utc time: Thu Oct 10 02:01:00 2024
us: 0
selected local time: Thu Oct 10 05:01:00 2024
selected utc time: Thu Oct 10 02:01:00 2024
us: 0
selected local time: Thu Oct 10 11:32:57 2024
selected utc time: Thu Oct 10 08:32:57 2024
us: 123456
selected local time: Thu Oct 10 11:33:09 2024
selected utc time: Thu Oct 10 08:33:09 2024
us: 123456
I see that text query (value or TSV format) inserted data in server time zone.
Data that inserted via Client.Insert() has utc time zone. Time zone of text insert and time zone of binary insert is different!
I need unification of time working.

Also will be very good if I can insert data in client local time zone. I did not found way to insert time in client time zone in text formats.

There is output of the client:
SELECT *
FROM test_datetime64

Query id: 560fd02a-cb6c-4303-8947-2c9727cd1793

┌───────────────────────dt64─┐
1. │ 2024-10-10 17:33:09.123456 │
└────────────────────────────┘
┌───────────────────────dt64─┐
2. │ 2024-10-10 11:00:00.000000 │
3. │ 2024-10-10 11:00:00.000000 │
4. │ 2024-10-10 11:01:00.000000 │
5. │ 2024-10-10 11:01:00.000000 │
6. │ 2024-10-10 17:32:57.123456 │
└────────────────────────────┘

Beitragsleitfaden

Für dieses Repository ist kein Beitragsleitfaden indexiert

Rechercherichtung

Start with the DateTime64Example code in the issue and reproduce the inserts with the server in Asia/Tokyo and clients in Europe/Paris and Europe/Moscow. Compare text/TSV inserts with Client.Insert(), then trace their DateTime64 timezone handling. Done means the insertion paths have documented, consistent timezone behavior and the requested client-local option is addressed.

Vom Indexierungsmodell aus dem Issue-Text verfasst.

Bewertung

Tech-Stack
cpp
Bereich
databases
Issue-Typ
Bug
Schwierigkeit
4/5
Geschätzter Aufwand
3-5 Tage
Aktivitätsstatus
Ruhig
Klarheit
Größtenteils klar
Anfängerfreundlichkeit
45/100

Neue Issues direkt in Ihr Postfach

Eine kurze Übersicht über anfängerfreundliche GitHub-Issues.