allow encoding non-utc datetimes in rowbinary

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - gracefully handle `connection: closed` response from server https://github.com/plausible/ch/pull/211
 - allow non-UTC `DateTime.t()` in query params https://github.com/plausible/ch/pull/223
+- allow non-UTC `DateTime.t()` when encoding RowBinary https://github.com/plausible/ch/pull/225
 
 ## 0.2.9 (2024-11-04)
 

README.md

@@ -257,17 +257,33 @@ Mix.install([:ch, :tz])
 "2023-04-26 01:45:12+08:00 CST Asia/Taipei" = to_string(taipei)
 ```
 
-Encoding non-UTC datetimes raises an `ArgumentError`
+Encoding non-UTC datetimes works but might be slow due to timezone conversion:
 
 ```elixir
-Ch.query!(pid, "CREATE TABLE ch_datetimes(datetime DateTime) ENGINE Null")
+Mix.install([:ch, :tz])
+
+:ok = Calendar.put_time_zone_database(Tz.TimeZoneDatabase)
+
+{:ok, pid} = Ch.start_link()
+
+Ch.query!(pid, "CREATE TABLE ch_datetimes(name String, datetime DateTime) ENGINE Memory")
 
 naive = NaiveDateTime.utc_now()
 utc = DateTime.utc_now()
 taipei = DateTime.shift_zone!(utc, "Asia/Taipei")
 
-# ** (ArgumentError) non-UTC timezones are not supported for encoding: 2023-04-26 01:49:43.044569+08:00 CST Asia/Taipei
-Ch.query!(pid, "INSERT INTO ch_datetimes(datetime) FORMAT RowBinary", [[naive], [utc], [taipei]], types: ["DateTime"])
+rows = [["naive", naive], ["utc", utc], ["taipei", taipei]]
+
+Ch.query!(pid, "INSERT INTO ch_datetimes(name, datetime) FORMAT RowBinary", rows, types: ["String", "DateTime"])
+
+%Ch.Result{
+  rows: [
+    ["naive", ~U[2024-12-21 05:24:40Z]],
+    ["utc", ~U[2024-12-21 05:24:40Z]],
+    ["taipei", ~U[2024-12-21 05:24:40Z]]
+  ]
+} =
+  Ch.query!(pid, "SELECT name, CAST(datetime as DateTime('UTC')) FROM ch_datetimes")
 ```
 
 ## [Benchmarks](./bench)

lib/ch/row_binary.ex

@@ -308,7 +308,7 @@ defmodule Ch.RowBinary do
   end
 
   def encode(:datetime, %DateTime{} = datetime) do
-    raise ArgumentError, "non-UTC timezones are not supported for encoding: #{datetime}"
+    encode(:datetime, DateTime.shift_zone!(datetime, "Etc/UTC"))
   end
 
   def encode(:datetime, nil), do: <<0::32>>

test/ch/connection_test.exs

@@ -141,6 +141,37 @@ defmodule Ch.ConnectionTest do
     assert inspect(jp) == "#DateTime<2021-01-01 21:34:56+09:00 JST Asia/Tokyo>"
   end
 
+  test "non-utc datetime rowbinary encoding", %{conn: conn} do
+    Ch.query!(
+      conn,
+      "create table ch_non_utc_datetimes(name String, datetime DateTime) engine Memory"
+    )
+
+    on_exit(fn -> Ch.Test.sql_exec("drop table ch_non_utc_datetimes") end)
+
+    utc = ~U[2024-12-21 05:35:19.886393Z]
+
+    taipei = DateTime.shift_zone!(utc, "Asia/Taipei")
+    tokyo = DateTime.shift_zone!(utc, "Asia/Tokyo")
+    vienna = DateTime.shift_zone!(utc, "Europe/Vienna")
+
+    rows = [["taipei", taipei], ["tokyo", tokyo], ["vienna", vienna]]
+
+    Ch.query!(conn, "insert into ch_non_utc_datetimes(name, datetime) format RowBinary", rows,
+      types: ["String", "DateTime"]
+    )
+
+    result =
+      conn
+      |> Ch.query!("select name, cast(datetime as DateTime('UTC')) from ch_non_utc_datetimes")
+      |> Map.fetch!(:rows)
+      |> Map.new(fn [name, datetime] -> {name, datetime} end)
+
+    assert result["taipei"] == ~U[2024-12-21 05:35:19Z]
+    assert result["tokyo"] == ~U[2024-12-21 05:35:19Z]
+    assert result["vienna"] == ~U[2024-12-21 05:35:19Z]
+  end
+
   test "utc datetime64 query param encoding", %{conn: conn} do
     utc = ~U[2021-01-01 12:00:00.123456Z]
     msk = DateTime.new!(~D[2021-01-01], ~T[15:00:00.123456], "Europe/Moscow")