From 2ab86081667d879574d7be11c6aa2750f908cd6d Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Fri, 11 Jul 2025 12:51:10 +0200
Subject: [PATCH 01/21] multipart requests

---
 lib/ch/connection.ex | 35 +++++++++++++++++++++++++++++++++--
 mix.exs              |  1 +
 mix.lock             |  2 ++
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/lib/ch/connection.ex b/lib/ch/connection.ex
index 40970ae..9e247c4 100644
--- a/lib/ch/connection.ex
+++ b/lib/ch/connection.ex
@@ -2,6 +2,7 @@ defmodule Ch.Connection do
   @moduledoc false
   use DBConnection
   require Logger
+  alias Multipart.Part
   alias Ch.{Error, Query, Result}
   alias Mint.HTTP1, as: HTTP
 
@@ -214,7 +215,9 @@ defmodule Ch.Connection do
 
   def handle_execute(%Query{command: :insert} = query, params, opts, conn) do
     conn = maybe_reconnect(conn)
-    {query_params, extra_headers, body} = params
+
+    multipart_request = Keyword.get(opts, :multipart_request, true)
+    {query_params, extra_headers, body} = parse_params(params, multipart_request)
 
     path = path(conn, query_params, opts)
     headers = headers(conn, extra_headers, opts)
@@ -233,7 +236,9 @@ defmodule Ch.Connection do
 
   def handle_execute(query, params, opts, conn) do
     conn = maybe_reconnect(conn)
-    {query_params, extra_headers, body} = params
+
+    multipart_request = Keyword.get(opts, :multipart_request, true)
+    {query_params, extra_headers, body} = parse_params(params, multipart_request)
 
     path = path(conn, query_params, opts)
     headers = headers(conn, extra_headers, opts)
@@ -379,6 +384,32 @@ defmodule Ch.Connection do
     end
   end
 
+  @spec parse_params(tuple, boolean) :: tuple
+  defp parse_params({query_params, headers, body}, true = _multipart?) when is_binary(body) do
+    body = to_string(body)
+
+    multipart =
+      query_params
+      |> Enum.reduce(Multipart.new(), fn {k, v}, acc ->
+        Multipart.add_part(acc, Part.text_field(v, k))
+      end)
+      |> Multipart.add_part(Part.text_field(body, "query"))
+
+    content_length = Multipart.content_length(multipart)
+    content_type = Multipart.content_type(multipart, "multipart/form-data")
+
+    multipart_headers = [
+      {"Content-Type", content_type},
+      {"Content-Length", to_string(content_length)}
+    ]
+
+    {[], headers ++ multipart_headers, Multipart.body_binary(multipart)}
+  end
+
+  defp parse_params(params, _) do
+    params
+  end
+
   defp get_header(headers, key) do
     case List.keyfind(headers, key, 0) do
       {_, value} -> value
diff --git a/mix.exs b/mix.exs
index dd11049..c8f704e 100644
--- a/mix.exs
+++ b/mix.exs
@@ -41,6 +41,7 @@ defmodule Ch.MixProject do
       {:db_connection, "~> 2.0"},
       {:jason, "~> 1.0"},
       {:decimal, "~> 2.0"},
+      {:multipart, "~> 0.4.0"},
       {:ecto, "~> 3.13.0", optional: true},
       {:benchee, "~> 1.0", only: [:bench]},
       {:dialyxir, "~> 1.0", only: [:dev], runtime: false},
diff --git a/mix.lock b/mix.lock
index 0e57a37..94448ac 100644
--- a/mix.lock
+++ b/mix.lock
@@ -13,7 +13,9 @@
   "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
   "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
   "makeup_erlang": {:hex, :makeup_erlang, "1.0.2", "03e1804074b3aa64d5fad7aa64601ed0fb395337b982d9bcf04029d68d51b6a7", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "af33ff7ef368d5893e4a267933e7744e46ce3cf1f61e2dccf53a111ed3aa3727"},
+  "mime": {:hex, :mime, "2.0.7", "b8d739037be7cd402aee1ba0306edfdef982687ee7e9859bee6198c1e7e2f128", [:mix], [], "hexpm", "6171188e399ee16023ffc5b76ce445eb6d9672e2e241d2df6050f3c771e80ccd"},
   "mint": {:hex, :mint, "1.7.1", "113fdb2b2f3b59e47c7955971854641c61f378549d73e829e1768de90fc1abf1", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "fceba0a4d0f24301ddee3024ae116df1c3f4bb7a563a731f45fdfeb9d39a231b"},
+  "multipart": {:hex, :multipart, "0.4.0", "634880a2148d4555d050963373d0e3bbb44a55b2badd87fa8623166172e9cda0", [:mix], [{:mime, "~> 1.2 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm", "3c5604bc2fb17b3137e5d2abdf5dacc2647e60c5cc6634b102cf1aef75a06f0a"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.4.2", "8efba0122db06df95bfaa78f791344a89352ba04baedd3849593bfce4d0dc1c6", [:mix], [], "hexpm", "4b21398942dda052b403bbe1da991ccd03a053668d147d53fb8c4e0efe09c973"},
   "statistex": {:hex, :statistex, "1.1.0", "7fec1eb2f580a0d2c1a05ed27396a084ab064a40cfc84246dbfb0c72a5c761e5", [:mix], [], "hexpm", "f5950ea26ad43246ba2cce54324ac394a4e7408fdcf98b8e230f503a0cba9cf5"},
   "telemetry": {:hex, :telemetry, "1.3.0", "fedebbae410d715cf8e7062c96a1ef32ec22e764197f70cda73d82778d61e7a2", [:rebar3], [], "hexpm", "7015fc8919dbe63764f4b4b87a95b7c0996bd539e0d499be6ec9d7f3875b79e6"},

From 76274b77363f1414033d4b5eb9fef57d3480ad3b Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Fri, 11 Jul 2025 12:52:54 +0200
Subject: [PATCH 02/21] to false

---
 lib/ch/connection.ex | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/ch/connection.ex b/lib/ch/connection.ex
index 9e247c4..46c3600 100644
--- a/lib/ch/connection.ex
+++ b/lib/ch/connection.ex
@@ -216,7 +216,7 @@ defmodule Ch.Connection do
   def handle_execute(%Query{command: :insert} = query, params, opts, conn) do
     conn = maybe_reconnect(conn)
 
-    multipart_request = Keyword.get(opts, :multipart_request, true)
+    multipart_request = Keyword.get(opts, :multipart_request, false)
     {query_params, extra_headers, body} = parse_params(params, multipart_request)
 
     path = path(conn, query_params, opts)
@@ -237,7 +237,7 @@ defmodule Ch.Connection do
   def handle_execute(query, params, opts, conn) do
     conn = maybe_reconnect(conn)
 
-    multipart_request = Keyword.get(opts, :multipart_request, true)
+    multipart_request = Keyword.get(opts, :multipart_request, false)
     {query_params, extra_headers, body} = parse_params(params, multipart_request)
 
     path = path(conn, query_params, opts)

From 828133c5fabfad10e13ccec9dde49b4830c10519 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Fri, 11 Jul 2025 13:11:05 +0200
Subject: [PATCH 03/21] update docs and interface

---
 README.md            | 20 ++++++++++++++++++++
 lib/ch.ex            |  1 +
 lib/ch/connection.ex |  8 ++++----
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 22de38c..6222ed5 100644
--- a/README.md
+++ b/README.md
@@ -161,6 +161,26 @@ settings = [async_insert: 1]
   Ch.query!(pid, "SHOW SETTINGS LIKE 'async_insert'", [], settings: settings)
 ```
 
+#### Sending request as multipart
+
+```elixir
+{:ok, pid} = Ch.start_link()
+
+Ch.query!(pid, "CREATE TABLE IF NOT EXISTS ch_demo(id UInt64) ENGINE Null")
+
+{:ok, %Ch.Result{rows: [[0], [1], [2]]}} =
+  Ch.query(pid, "SELECT * FROM system.numbers LIMIT {$0:UInt8}", [3], multipart: true)
+
+{:ok, %Ch.Result{rows: [[0], [1], [2]]}} =
+  Ch.query(pid, "SELECT * FROM system.numbers LIMIT {limit:UInt8}", %{"limit" => 3}, multipart: true)
+
+%Ch.Result{num_rows: 2} =
+  Ch.query!(pid, "INSERT INTO ch_demo(id) VALUES ({$0:UInt8}), ({$1:UInt32})", [0, 1], multipart: true)
+```
+
+Adding the `multipart: true` option to a query sends its Clickhouse request as a multipart request.
+This encodes all the request data inside the body, and leaves the URL empty.
+
 ## Caveats
 
 #### NULL in RowBinary
diff --git a/lib/ch.ex b/lib/ch.ex
index 52a5f6b..758627f 100644
--- a/lib/ch.ex
+++ b/lib/ch.ex
@@ -76,6 +76,7 @@ defmodule Ch do
     * `:headers` - Custom HTTP headers for the request
     * `:format` - Custom response format for the request
     * `:decode` - Whether to automatically decode the response
+    * `:multipart` - Whether to use multipart/form-data encoding for the request. Not supported for RowBinary inserts or streaming.
     * [`DBConnection.connection_option()`](https://hexdocs.pm/db_connection/DBConnection.html#t:connection_option/0)
 
   """
diff --git a/lib/ch/connection.ex b/lib/ch/connection.ex
index 46c3600..351a5d7 100644
--- a/lib/ch/connection.ex
+++ b/lib/ch/connection.ex
@@ -216,8 +216,8 @@ defmodule Ch.Connection do
   def handle_execute(%Query{command: :insert} = query, params, opts, conn) do
     conn = maybe_reconnect(conn)
 
-    multipart_request = Keyword.get(opts, :multipart_request, false)
-    {query_params, extra_headers, body} = parse_params(params, multipart_request)
+    multipart = Keyword.get(opts, :multipart, false)
+    {query_params, extra_headers, body} = parse_params(params, multipart)
 
     path = path(conn, query_params, opts)
     headers = headers(conn, extra_headers, opts)
@@ -237,8 +237,8 @@ defmodule Ch.Connection do
   def handle_execute(query, params, opts, conn) do
     conn = maybe_reconnect(conn)
 
-    multipart_request = Keyword.get(opts, :multipart_request, false)
-    {query_params, extra_headers, body} = parse_params(params, multipart_request)
+    multipart = Keyword.get(opts, :multipart, false)
+    {query_params, extra_headers, body} = parse_params(params, multipart)
 
     path = path(conn, query_params, opts)
     headers = headers(conn, extra_headers, opts)

From 23db2b9056f7c4a590c92697fa8cbf3473f23286 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Fri, 11 Jul 2025 13:13:16 +0200
Subject: [PATCH 04/21] remove to string

---
 lib/ch/connection.ex | 2 --
 1 file changed, 2 deletions(-)

diff --git a/lib/ch/connection.ex b/lib/ch/connection.ex
index 351a5d7..76679f5 100644
--- a/lib/ch/connection.ex
+++ b/lib/ch/connection.ex
@@ -386,8 +386,6 @@ defmodule Ch.Connection do
 
   @spec parse_params(tuple, boolean) :: tuple
   defp parse_params({query_params, headers, body}, true = _multipart?) when is_binary(body) do
-    body = to_string(body)
-
     multipart =
       query_params
       |> Enum.reduce(Multipart.new(), fn {k, v}, acc ->

From 66020ff9cf1df99bce5a45b4437f41ef0bcb13ac Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Tue, 29 Jul 2025 09:49:24 +0200
Subject: [PATCH 05/21] custom multipart and slight refactor

---
 lib/ch/connection.ex        |  33 +----------
 lib/ch/encode/multipart.ex  |  86 ++++++++++++++++++++++++++++
 lib/ch/encode/parameters.ex | 109 ++++++++++++++++++++++++++++++++++++
 lib/ch/query.ex             | 104 +---------------------------------
 mix.exs                     |   1 -
 5 files changed, 200 insertions(+), 133 deletions(-)
 create mode 100644 lib/ch/encode/multipart.ex
 create mode 100644 lib/ch/encode/parameters.ex

diff --git a/lib/ch/connection.ex b/lib/ch/connection.ex
index 76679f5..40970ae 100644
--- a/lib/ch/connection.ex
+++ b/lib/ch/connection.ex
@@ -2,7 +2,6 @@ defmodule Ch.Connection do
   @moduledoc false
   use DBConnection
   require Logger
-  alias Multipart.Part
   alias Ch.{Error, Query, Result}
   alias Mint.HTTP1, as: HTTP
 
@@ -215,9 +214,7 @@ defmodule Ch.Connection do
 
   def handle_execute(%Query{command: :insert} = query, params, opts, conn) do
     conn = maybe_reconnect(conn)
-
-    multipart = Keyword.get(opts, :multipart, false)
-    {query_params, extra_headers, body} = parse_params(params, multipart)
+    {query_params, extra_headers, body} = params
 
     path = path(conn, query_params, opts)
     headers = headers(conn, extra_headers, opts)
@@ -236,9 +233,7 @@ defmodule Ch.Connection do
 
   def handle_execute(query, params, opts, conn) do
     conn = maybe_reconnect(conn)
-
-    multipart = Keyword.get(opts, :multipart, false)
-    {query_params, extra_headers, body} = parse_params(params, multipart)
+    {query_params, extra_headers, body} = params
 
     path = path(conn, query_params, opts)
     headers = headers(conn, extra_headers, opts)
@@ -384,30 +379,6 @@ defmodule Ch.Connection do
     end
   end
 
-  @spec parse_params(tuple, boolean) :: tuple
-  defp parse_params({query_params, headers, body}, true = _multipart?) when is_binary(body) do
-    multipart =
-      query_params
-      |> Enum.reduce(Multipart.new(), fn {k, v}, acc ->
-        Multipart.add_part(acc, Part.text_field(v, k))
-      end)
-      |> Multipart.add_part(Part.text_field(body, "query"))
-
-    content_length = Multipart.content_length(multipart)
-    content_type = Multipart.content_type(multipart, "multipart/form-data")
-
-    multipart_headers = [
-      {"Content-Type", content_type},
-      {"Content-Length", to_string(content_length)}
-    ]
-
-    {[], headers ++ multipart_headers, Multipart.body_binary(multipart)}
-  end
-
-  defp parse_params(params, _) do
-    params
-  end
-
   defp get_header(headers, key) do
     case List.keyfind(headers, key, 0) do
       {_, value} -> value
diff --git a/lib/ch/encode/multipart.ex b/lib/ch/encode/multipart.ex
new file mode 100644
index 0000000..25fa42e
--- /dev/null
+++ b/lib/ch/encode/multipart.ex
@@ -0,0 +1,86 @@
+defmodule Ch.Encode.Multipart do
+  @moduledoc false
+
+  alias Ch.Encode.Parameters
+
+  @doc """
+  Encodes a query statement and params into a multipart request.
+  """
+  @spec encode(iodata, map, [Ch.query_option()]) ::
+          {list, Mint.Types.headers(), iodata}
+  def encode(statement, params, opts) do
+    types = Keyword.get(opts, :types)
+    default_format = if types, do: "RowBinary", else: "RowBinaryWithNamesAndTypes"
+    format = Keyword.get(opts, :format) || default_format
+
+    boundary = "ChFormBoundary" <> Base.url_encode64(:crypto.strong_rand_bytes(24))
+    content_type = "multipart/form-data; boundary=\"#{boundary}\""
+    enc_boundary = "--#{boundary}\r\n"
+
+    multipart =
+      params
+      |> multipart_params(enc_boundary)
+      |> add_multipart_part("query", statement, enc_boundary)
+      |> then(&[&1 | "--#{boundary}--\r\n"])
+
+    headers = [{"x-clickhouse-format", format}, {"content-type", content_type} | headers(opts)]
+
+    {_no_query_params = [], headers, multipart}
+  end
+
+  defp multipart_params(params, boundary) when is_map(params) do
+    multipart_named_params(Map.to_list(params), boundary, [])
+  end
+
+  defp multipart_params(params, boundary) when is_list(params) do
+    multipart_positional_params(params, 0, boundary, [])
+  end
+
+  defp multipart_named_params([{name, value} | params], boundary, acc) do
+    acc =
+      add_multipart_part(
+        acc,
+        "param_" <> URI.encode_www_form(name),
+        Parameters.encode(value),
+        boundary
+      )
+
+    multipart_named_params(params, boundary, acc)
+  end
+
+  defp multipart_named_params([], _boundary, acc), do: acc
+
+  defp multipart_positional_params([value | params], idx, boundary, acc) do
+    acc =
+      add_multipart_part(
+        acc,
+        "param_$" <> Integer.to_string(idx),
+        Parameters.encode(value),
+        boundary
+      )
+
+    multipart_positional_params(params, idx + 1, boundary, acc)
+  end
+
+  defp multipart_positional_params([], _idx, _boundary, acc), do: acc
+
+  @compile inline: [add_multipart_part: 4]
+  defp add_multipart_part(multipart, name, value, boundary) do
+    part = [
+      boundary,
+      "content-disposition: form-data; name=\"",
+      name,
+      "\"\r\n\r\n",
+      value,
+      "\r\n"
+    ]
+
+    case multipart do
+      [] -> part
+      _ -> [multipart | part]
+    end
+  end
+
+  @spec headers(Keyword.t()) :: Mint.Types.headers()
+  defp headers(opts), do: Keyword.get(opts, :headers, [])
+end
diff --git a/lib/ch/encode/parameters.ex b/lib/ch/encode/parameters.ex
new file mode 100644
index 0000000..818f4fb
--- /dev/null
+++ b/lib/ch/encode/parameters.ex
@@ -0,0 +1,109 @@
+defmodule Ch.Encode.Parameters do
+  @moduledoc false
+
+  @doc """
+  Encodes a map/list of parameters into a list of clickhouse parameter tuples.
+
+  The format is `[{"param_<key>", "<value>"}, ...]`.
+  """
+  @spec encode_many(map | [term]) :: [{String.t(), String.t()}]
+  def encode_many(params) when is_map(params) do
+    Enum.map(params, fn {k, v} -> {"param_#{k}", encode(v)} end)
+  end
+
+  def encode_many(params) when is_list(params) do
+    params
+    |> Enum.with_index()
+    |> Enum.map(fn {v, idx} -> {"param_$#{idx}", encode(v)} end)
+  end
+
+  @doc """
+  Encodes a clickhouse parameter to a string.
+  """
+  @spec encode(term) :: binary
+  def encode(n) when is_integer(n), do: Integer.to_string(n)
+  def encode(f) when is_float(f), do: Float.to_string(f)
+
+  # TODO possibly speed up
+  # For more info see
+  # https://clickhouse.com/docs/en/interfaces/http#tabs-in-url-parameters
+  # "escaped" format is the same as https://clickhouse.com/docs/en/interfaces/formats#tabseparated-data-formatting
+  def encode(b) when is_binary(b) do
+    escape_param([{"\\", "\\\\"}, {"\t", "\\\t"}, {"\n", "\\\n"}], b)
+  end
+
+  def encode(b) when is_boolean(b), do: Atom.to_string(b)
+  def encode(%Decimal{} = d), do: Decimal.to_string(d, :normal)
+  def encode(%Date{} = date), do: Date.to_iso8601(date)
+  def encode(%NaiveDateTime{} = naive), do: NaiveDateTime.to_iso8601(naive)
+
+  def encode(%DateTime{microsecond: microsecond} = dt) do
+    dt = DateTime.shift_zone!(dt, "Etc/UTC")
+
+    case microsecond do
+      {val, precision} when val > 0 and precision > 0 ->
+        size = round(:math.pow(10, precision))
+        unix = DateTime.to_unix(dt, size)
+        seconds = div(unix, size)
+        fractional = rem(unix, size)
+
+        IO.iodata_to_binary([
+          Integer.to_string(seconds),
+          ?.,
+          String.pad_leading(Integer.to_string(fractional), precision, "0")
+        ])
+
+      _ ->
+        dt |> DateTime.to_unix(:second) |> Integer.to_string()
+    end
+  end
+
+  def encode(tuple) when is_tuple(tuple) do
+    IO.iodata_to_binary([?(, encode_array_params(Tuple.to_list(tuple)), ?)])
+  end
+
+  def encode(a) when is_list(a) do
+    IO.iodata_to_binary([?[, encode_array_params(a), ?]])
+  end
+
+  def encode(m) when is_map(m) do
+    IO.iodata_to_binary([?{, encode_map_params(Map.to_list(m)), ?}])
+  end
+
+  defp encode_array_params([last]), do: encode_array_param(last)
+
+  defp encode_array_params([s | rest]) do
+    [encode_array_param(s), ?, | encode_array_params(rest)]
+  end
+
+  defp encode_array_params([] = empty), do: empty
+
+  defp encode_map_params([last]), do: encode_map_param(last)
+
+  defp encode_map_params([kv | rest]) do
+    [encode_map_param(kv), ?, | encode_map_params(rest)]
+  end
+
+  defp encode_map_params([] = empty), do: empty
+
+  defp encode_array_param(s) when is_binary(s) do
+    [?', escape_param([{"'", "''"}, {"\\", "\\\\"}], s), ?']
+  end
+
+  defp encode_array_param(%s{} = param) when s in [Date, NaiveDateTime] do
+    [?', encode(param), ?']
+  end
+
+  defp encode_array_param(v), do: encode(v)
+
+  defp encode_map_param({k, v}) do
+    [encode_array_param(k), ?:, encode_array_param(v)]
+  end
+
+  defp escape_param([{pattern, replacement} | escapes], param) do
+    param = String.replace(param, pattern, replacement)
+    escape_param(escapes, param)
+  end
+
+  defp escape_param([], param), do: param
+end
diff --git a/lib/ch/query.ex b/lib/ch/query.ex
index f5a9805..c1d9159 100644
--- a/lib/ch/query.ex
+++ b/lib/ch/query.ex
@@ -72,6 +72,7 @@ end
 
 defimpl DBConnection.Query, for: Ch.Query do
   alias Ch.{Query, Result, RowBinary}
+  alias Ch.Encode.{Multipart, Parameters}
 
   @spec parse(Query.t(), [Ch.query_option()]) :: Query.t()
   def parse(query, _opts), do: query
@@ -123,15 +124,12 @@ defimpl DBConnection.Query, for: Ch.Query do
         {_query_params = [], headers(opts), [statement, ?\n | data]}
 
       true ->
-        {query_params(params), headers(opts), statement}
+        {Parameters.encode_many(params), headers(opts), statement}
     end
   end
 
   def encode(%Query{statement: statement}, params, opts) do
-    types = Keyword.get(opts, :types)
-    default_format = if types, do: "RowBinary", else: "RowBinaryWithNamesAndTypes"
-    format = Keyword.get(opts, :format) || default_format
-    {query_params(params), [{"x-clickhouse-format", format} | headers(opts)], statement}
+    Multipart.encode(statement, params, opts)
   end
 
   defp format_row_binary?(statement) when is_binary(statement) do
@@ -207,102 +205,6 @@ defimpl DBConnection.Query, for: Ch.Query do
     end
   end
 
-  defp query_params(params) when is_map(params) do
-    Enum.map(params, fn {k, v} -> {"param_#{k}", encode_param(v)} end)
-  end
-
-  defp query_params(params) when is_list(params) do
-    params
-    |> Enum.with_index()
-    |> Enum.map(fn {v, idx} -> {"param_$#{idx}", encode_param(v)} end)
-  end
-
-  defp encode_param(n) when is_integer(n), do: Integer.to_string(n)
-  defp encode_param(f) when is_float(f), do: Float.to_string(f)
-
-  # TODO possibly speed up
-  # For more info see
-  # https://clickhouse.com/docs/en/interfaces/http#tabs-in-url-parameters
-  # "escaped" format is the same as https://clickhouse.com/docs/en/interfaces/formats#tabseparated-data-formatting
-  defp encode_param(b) when is_binary(b) do
-    escape_param([{"\\", "\\\\"}, {"\t", "\\\t"}, {"\n", "\\\n"}], b)
-  end
-
-  defp encode_param(b) when is_boolean(b), do: Atom.to_string(b)
-  defp encode_param(%Decimal{} = d), do: Decimal.to_string(d, :normal)
-  defp encode_param(%Date{} = date), do: Date.to_iso8601(date)
-  defp encode_param(%NaiveDateTime{} = naive), do: NaiveDateTime.to_iso8601(naive)
-
-  defp encode_param(%DateTime{microsecond: microsecond} = dt) do
-    dt = DateTime.shift_zone!(dt, "Etc/UTC")
-
-    case microsecond do
-      {val, precision} when val > 0 and precision > 0 ->
-        size = round(:math.pow(10, precision))
-        unix = DateTime.to_unix(dt, size)
-        seconds = div(unix, size)
-        fractional = rem(unix, size)
-
-        IO.iodata_to_binary([
-          Integer.to_string(seconds),
-          ?.,
-          String.pad_leading(Integer.to_string(fractional), precision, "0")
-        ])
-
-      _ ->
-        dt |> DateTime.to_unix(:second) |> Integer.to_string()
-    end
-  end
-
-  defp encode_param(tuple) when is_tuple(tuple) do
-    IO.iodata_to_binary([?(, encode_array_params(Tuple.to_list(tuple)), ?)])
-  end
-
-  defp encode_param(a) when is_list(a) do
-    IO.iodata_to_binary([?[, encode_array_params(a), ?]])
-  end
-
-  defp encode_param(m) when is_map(m) do
-    IO.iodata_to_binary([?{, encode_map_params(Map.to_list(m)), ?}])
-  end
-
-  defp encode_array_params([last]), do: encode_array_param(last)
-
-  defp encode_array_params([s | rest]) do
-    [encode_array_param(s), ?, | encode_array_params(rest)]
-  end
-
-  defp encode_array_params([] = empty), do: empty
-
-  defp encode_map_params([last]), do: encode_map_param(last)
-
-  defp encode_map_params([kv | rest]) do
-    [encode_map_param(kv), ?, | encode_map_params(rest)]
-  end
-
-  defp encode_map_params([] = empty), do: empty
-
-  defp encode_array_param(s) when is_binary(s) do
-    [?', escape_param([{"'", "''"}, {"\\", "\\\\"}], s), ?']
-  end
-
-  defp encode_array_param(%s{} = param) when s in [Date, NaiveDateTime] do
-    [?', encode_param(param), ?']
-  end
-
-  defp encode_array_param(v), do: encode_param(v)
-
-  defp encode_map_param({k, v}) do
-    [encode_array_param(k), ?:, encode_array_param(v)]
-  end
-
-  defp escape_param([{pattern, replacement} | escapes], param) do
-    param = String.replace(param, pattern, replacement)
-    escape_param(escapes, param)
-  end
-
-  defp escape_param([], param), do: param
-
   @spec headers(Keyword.t()) :: Mint.Types.headers()
   defp headers(opts), do: Keyword.get(opts, :headers, [])
 end
diff --git a/mix.exs b/mix.exs
index c8f704e..dd11049 100644
--- a/mix.exs
+++ b/mix.exs
@@ -41,7 +41,6 @@ defmodule Ch.MixProject do
       {:db_connection, "~> 2.0"},
       {:jason, "~> 1.0"},
       {:decimal, "~> 2.0"},
-      {:multipart, "~> 0.4.0"},
       {:ecto, "~> 3.13.0", optional: true},
       {:benchee, "~> 1.0", only: [:bench]},
       {:dialyxir, "~> 1.0", only: [:dev], runtime: false},

From 482a42fd9ef538462c4e0ee0323fea9a4fa54068 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Tue, 29 Jul 2025 09:53:24 +0200
Subject: [PATCH 06/21] merge

---
 lib/ch/encode/parameters.ex | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/ch/encode/parameters.ex b/lib/ch/encode/parameters.ex
index 818f4fb..0ac0828 100644
--- a/lib/ch/encode/parameters.ex
+++ b/lib/ch/encode/parameters.ex
@@ -33,9 +33,11 @@ defmodule Ch.Encode.Parameters do
   end
 
   def encode(b) when is_boolean(b), do: Atom.to_string(b)
+  def encode(nil), do: "\\N"
   def encode(%Decimal{} = d), do: Decimal.to_string(d, :normal)
   def encode(%Date{} = date), do: Date.to_iso8601(date)
   def encode(%NaiveDateTime{} = naive), do: NaiveDateTime.to_iso8601(naive)
+  def encode(%Time{} = time), do: Time.to_iso8601(time)
 
   def encode(%DateTime{microsecond: microsecond} = dt) do
     dt = DateTime.shift_zone!(dt, "Etc/UTC")
@@ -90,6 +92,8 @@ defmodule Ch.Encode.Parameters do
     [?', escape_param([{"'", "''"}, {"\\", "\\\\"}], s), ?']
   end
 
+  defp encode_array_param(nil), do: "null"
+
   defp encode_array_param(%s{} = param) when s in [Date, NaiveDateTime] do
     [?', encode(param), ?']
   end

From 5191d07e060c2b0bd6f0a8925f6b413fa9467953 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Tue, 29 Jul 2025 10:01:05 +0200
Subject: [PATCH 07/21] docs

---
 README.md | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index f044dfe..0f0b1f5 100644
--- a/README.md
+++ b/README.md
@@ -163,23 +163,8 @@ settings = [async_insert: 1]
 
 #### Sending request as multipart
 
-```elixir
-{:ok, pid} = Ch.start_link()
-
-Ch.query!(pid, "CREATE TABLE IF NOT EXISTS ch_demo(id UInt64) ENGINE Null")
-
-{:ok, %Ch.Result{rows: [[0], [1], [2]]}} =
-  Ch.query(pid, "SELECT * FROM system.numbers LIMIT {$0:UInt8}", [3], multipart: true)
-
-{:ok, %Ch.Result{rows: [[0], [1], [2]]}} =
-  Ch.query(pid, "SELECT * FROM system.numbers LIMIT {limit:UInt8}", %{"limit" => 3}, multipart: true)
-
-%Ch.Result{num_rows: 2} =
-  Ch.query!(pid, "INSERT INTO ch_demo(id) VALUES ({$0:UInt8}), ({$1:UInt32})", [0, 1], multipart: true)
-```
-
-Adding the `multipart: true` option to a query sends its Clickhouse request as a multipart request.
-This encodes all the request data inside the body, and leaves the URL empty.
+SELECT queries will be automatically sent as multipart requests.
+INSERT queries and streams are treated normally.
 
 ## Caveats
 

From 22207b1a9f0a4b3f45ed20407615a87c524a4154 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Tue, 29 Jul 2025 10:03:14 +0200
Subject: [PATCH 08/21] doc title

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 0f0b1f5..0bece3e 100644
--- a/README.md
+++ b/README.md
@@ -161,7 +161,7 @@ settings = [async_insert: 1]
   Ch.query!(pid, "SHOW SETTINGS LIKE 'async_insert'", [], settings: settings)
 ```
 
-#### Sending request as multipart
+#### Multipart requests
 
 SELECT queries will be automatically sent as multipart requests.
 INSERT queries and streams are treated normally.

From d21d7abf2a7280cc2526d56c1d0df92ba5c738e0 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Tue, 29 Jul 2025 10:04:55 +0200
Subject: [PATCH 09/21] more cleanup

---
 lib/ch.ex | 1 -
 mix.lock  | 2 --
 2 files changed, 3 deletions(-)

diff --git a/lib/ch.ex b/lib/ch.ex
index 7346345..8b12e2c 100644
--- a/lib/ch.ex
+++ b/lib/ch.ex
@@ -76,7 +76,6 @@ defmodule Ch do
     * `:headers` - Custom HTTP headers for the request
     * `:format` - Custom response format for the request
     * `:decode` - Whether to automatically decode the response
-    * `:multipart` - Whether to use multipart/form-data encoding for the request. Not supported for RowBinary inserts or streaming.
     * [`DBConnection.connection_option()`](https://hexdocs.pm/db_connection/DBConnection.html#t:connection_option/0)
 
   """
diff --git a/mix.lock b/mix.lock
index 94448ac..0e57a37 100644
--- a/mix.lock
+++ b/mix.lock
@@ -13,9 +13,7 @@
   "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
   "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
   "makeup_erlang": {:hex, :makeup_erlang, "1.0.2", "03e1804074b3aa64d5fad7aa64601ed0fb395337b982d9bcf04029d68d51b6a7", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "af33ff7ef368d5893e4a267933e7744e46ce3cf1f61e2dccf53a111ed3aa3727"},
-  "mime": {:hex, :mime, "2.0.7", "b8d739037be7cd402aee1ba0306edfdef982687ee7e9859bee6198c1e7e2f128", [:mix], [], "hexpm", "6171188e399ee16023ffc5b76ce445eb6d9672e2e241d2df6050f3c771e80ccd"},
   "mint": {:hex, :mint, "1.7.1", "113fdb2b2f3b59e47c7955971854641c61f378549d73e829e1768de90fc1abf1", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "fceba0a4d0f24301ddee3024ae116df1c3f4bb7a563a731f45fdfeb9d39a231b"},
-  "multipart": {:hex, :multipart, "0.4.0", "634880a2148d4555d050963373d0e3bbb44a55b2badd87fa8623166172e9cda0", [:mix], [{:mime, "~> 1.2 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm", "3c5604bc2fb17b3137e5d2abdf5dacc2647e60c5cc6634b102cf1aef75a06f0a"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.4.2", "8efba0122db06df95bfaa78f791344a89352ba04baedd3849593bfce4d0dc1c6", [:mix], [], "hexpm", "4b21398942dda052b403bbe1da991ccd03a053668d147d53fb8c4e0efe09c973"},
   "statistex": {:hex, :statistex, "1.1.0", "7fec1eb2f580a0d2c1a05ed27396a084ab064a40cfc84246dbfb0c72a5c761e5", [:mix], [], "hexpm", "f5950ea26ad43246ba2cce54324ac394a4e7408fdcf98b8e230f503a0cba9cf5"},
   "telemetry": {:hex, :telemetry, "1.3.0", "fedebbae410d715cf8e7062c96a1ef32ec22e764197f70cda73d82778d61e7a2", [:rebar3], [], "hexpm", "7015fc8919dbe63764f4b4b87a95b7c0996bd539e0d499be6ec9d7f3875b79e6"},

From 3bee9258c615827b3d64d670ee5fed0e8047b2c5 Mon Sep 17 00:00:00 2001
From: hawkyre <hawkyre@gmail.com>
Date: Mon, 18 Aug 2025 15:03:07 +0200
Subject: [PATCH 10/21] send settings as params

---
 lib/ch/encode/multipart.ex | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/ch/encode/multipart.ex b/lib/ch/encode/multipart.ex
index 25fa42e..c058fde 100644
--- a/lib/ch/encode/multipart.ex
+++ b/lib/ch/encode/multipart.ex
@@ -10,6 +10,7 @@ defmodule Ch.Encode.Multipart do
           {list, Mint.Types.headers(), iodata}
   def encode(statement, params, opts) do
     types = Keyword.get(opts, :types)
+    settings = Keyword.get(opts, :settings, [])
     default_format = if types, do: "RowBinary", else: "RowBinaryWithNamesAndTypes"
     format = Keyword.get(opts, :format) || default_format
 
@@ -25,7 +26,7 @@ defmodule Ch.Encode.Multipart do
 
     headers = [{"x-clickhouse-format", format}, {"content-type", content_type} | headers(opts)]
 
-    {_no_query_params = [], headers, multipart}
+    {settings, headers, multipart}
   end
 
   defp multipart_params(params, boundary) when is_map(params) do

From 33ecfaf1fee0a55698c335257c9ce5d01a9d0414 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Tue, 19 Aug 2025 08:39:22 +0900
Subject: [PATCH 11/21] Bump actions/checkout from 4 to 5 (#270)

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
---
 .github/workflows/bench.yml      | 2 +-
 .github/workflows/spellcheck.yml | 4 ++--
 .github/workflows/test.yml       | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/bench.yml b/.github/workflows/bench.yml
index aa08d9e..a9d40fa 100644
--- a/.github/workflows/bench.yml
+++ b/.github/workflows/bench.yml
@@ -27,7 +27,7 @@ jobs:
             --health-retries 5
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - id: beam
         uses: erlef/setup-beam@v1
diff --git a/.github/workflows/spellcheck.yml b/.github/workflows/spellcheck.yml
index ff0ab78..3d39fe8 100644
--- a/.github/workflows/spellcheck.yml
+++ b/.github/workflows/spellcheck.yml
@@ -9,7 +9,7 @@ jobs:
   codespell:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: codespell-project/actions-codespell@v2
         with:
           check_filenames: true
@@ -18,5 +18,5 @@ jobs:
   typos:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: crate-ci/typos@master
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 06b25d0..05b2a6a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -62,7 +62,7 @@ jobs:
             --health-retries 5
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - id: beam
         uses: erlef/setup-beam@v1
@@ -87,7 +87,7 @@ jobs:
   format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: erlef/setup-beam@v1
         with:
           elixir-version: 1

From 574c14bfcc540a398183b5e43cac7a3ffdbf88ab Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:22:38 +0900
Subject: [PATCH 12/21] fix version check (#274)

---
 lib/ch/connection.ex | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/ch/connection.ex b/lib/ch/connection.ex
index f94b50a..b84846a 100644
--- a/lib/ch/connection.ex
+++ b/lib/ch/connection.ex
@@ -21,7 +21,7 @@ defmodule Ch.Connection do
           case DBConnection.Query.decode(handshake, responses, _opts = []) do
             %Result{rows: [[1, version]]} ->
               conn =
-                if version >= "24.10" do
+                if parse_version(version) >= parse_version("24.10") do
                   settings =
                     HTTP.get_private(conn, :settings, [])
                     |> Keyword.put_new(:input_format_binary_read_json_as_string, 1)
@@ -51,6 +51,17 @@ defmodule Ch.Connection do
     end
   end
 
+  defp parse_version(version) do
+    version
+    |> String.split(".")
+    |> Enum.flat_map(fn segment ->
+      case Integer.parse(segment) do
+        {int, _rest} -> [int]
+        :error -> []
+      end
+    end)
+  end
+
   @impl true
   @spec ping(conn) :: {:ok, conn} | {:disconnect, Mint.Types.error() | Error.t(), conn}
   def ping(conn) do

From a018df865801eecb288773ee9ee222e76efab0db Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:23:35 +0900
Subject: [PATCH 13/21] changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f48d1a..6845417 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+- fix version check for adding JSON settings https://github.com/plausible/ch/pull/274
+
 ## 0.5.4 (2025-07-22)
 
 - allow `nil` in params https://github.com/plausible/ch/pull/268

From ecc8a19f7002125548cee5942796d051e2e14551 Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:24:25 +0900
Subject: [PATCH 14/21] add older ClickHouse to CI

---
 .github/workflows/test.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 05b2a6a..66f32da 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -45,6 +45,9 @@ jobs:
             otp: 27.3.1
             clickhouse: 24.12.2.29
             timezone: UTC
+          - elixir: 1.18
+            otp: 28
+            clickhouse: 24.5.4.49
 
     services:
       clickhouse:

From cac0abd2c0ff245fb20079b70c84453c15a36399 Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:27:06 +0900
Subject: [PATCH 15/21] tag 'json as string' test as json

---
 test/ch/connection_test.exs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/ch/connection_test.exs b/test/ch/connection_test.exs
index b9003ed..394dcb6 100644
--- a/test/ch/connection_test.exs
+++ b/test/ch/connection_test.exs
@@ -593,6 +593,7 @@ defmodule Ch.ConnectionTest do
       assert_raise ArgumentError, fn -> Ch.query!(conn, "SELECT o FROM json") end
     end
 
+    @tag :json
     test "json as string", %{conn: conn} do
       # after v25 ClickHouse started rendering numbers in JSON as strings
       [[version]] = Ch.query!(conn, "select version()").rows

From a59d141a1ff1ff468188e2335e1ad84b929d2e8a Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:29:49 +0900
Subject: [PATCH 16/21] release v0.5.5

---
 CHANGELOG.md | 2 +-
 mix.exs      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6845417..88b6a72 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## Unreleased
+## 0.5.5 (2025-08-26)
 
 - fix version check for adding JSON settings https://github.com/plausible/ch/pull/274
 
diff --git a/mix.exs b/mix.exs
index 48ff301..e0dc05c 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,7 +2,7 @@ defmodule Ch.MixProject do
   use Mix.Project
 
   @source_url "https://github.com/plausible/ch"
-  @version "0.5.4"
+  @version "0.5.5"
 
   def project do
     [

From e0ccd54e435028314f17d25aea1b2bc5eb48c111 Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:30:08 +0900
Subject: [PATCH 17/21] update deps

---
 mix.lock | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mix.lock b/mix.lock
index 0e57a37..4abb55a 100644
--- a/mix.lock
+++ b/mix.lock
@@ -3,11 +3,11 @@
   "db_connection": {:hex, :db_connection, "2.8.0", "64fd82cfa6d8e25ec6660cea73e92a4cbc6a18b31343910427b702838c4b33b2", [:mix], [{:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "008399dae5eee1bf5caa6e86d204dcb44242c82b1ed5e22c881f2c34da201b15"},
   "decimal": {:hex, :decimal, "2.3.0", "3ad6255aa77b4a3c4f818171b12d237500e63525c2fd056699967a3e7ea20f62", [:mix], [], "hexpm", "a4d66355cb29cb47c3cf30e71329e58361cfcb37c34235ef3bf1d7bf3773aeac"},
   "deep_merge": {:hex, :deep_merge, "1.0.0", "b4aa1a0d1acac393bdf38b2291af38cb1d4a52806cf7a4906f718e1feb5ee961", [:mix], [], "hexpm", "ce708e5f094b9cd4e8f2be4f00d2f4250c4095be93f8cd6d018c753894885430"},
-  "dialyxir": {:hex, :dialyxir, "1.4.5", "ca1571ac18e0f88d4ab245f0b60fa31ff1b12cbae2b11bd25d207f865e8ae78a", [:mix], [{:erlex, ">= 0.2.7", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "b0fb08bb8107c750db5c0b324fa2df5ceaa0f9307690ee3c1f6ba5b9eb5d35c3"},
+  "dialyxir": {:hex, :dialyxir, "1.4.6", "7cca478334bf8307e968664343cbdb432ee95b4b68a9cba95bdabb0ad5bdfd9a", [:mix], [{:erlex, ">= 0.2.7", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "8cf5615c5cd4c2da6c501faae642839c8405b49f8aa057ad4ae401cb808ef64d"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
   "ecto": {:hex, :ecto, "3.13.2", "7d0c0863f3fc8d71d17fc3ad3b9424beae13f02712ad84191a826c7169484f01", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "669d9291370513ff56e7b7e7081b7af3283d02e046cf3d403053c557894a0b3e"},
   "erlex": {:hex, :erlex, "0.2.7", "810e8725f96ab74d17aac676e748627a07bc87eb950d2b83acd29dc047a30595", [:mix], [], "hexpm", "3ed95f79d1a844c3f6bf0cea61e0d5612a42ce56da9c03f01df538685365efb0"},
-  "ex_doc": {:hex, :ex_doc, "0.38.2", "504d25eef296b4dec3b8e33e810bc8b5344d565998cd83914ffe1b8503737c02", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "732f2d972e42c116a70802f9898c51b54916e542cc50968ac6980512ec90f42b"},
+  "ex_doc": {:hex, :ex_doc, "0.38.3", "ddafe36b8e9fe101c093620879f6604f6254861a95133022101c08e75e6c759a", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "ecaa785456a67f63b4e7d7f200e8832fa108279e7eb73fd9928e7e66215a01f9"},
   "hpax": {:hex, :hpax, "1.0.3", "ed67ef51ad4df91e75cc6a1494f851850c0bd98ebc0be6e81b026e765ee535aa", [:mix], [], "hexpm", "8eab6e1cfa8d5918c2ce4ba43588e894af35dbd8e91e6e55c817bca5847df34a"},
   "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},

From b3edc2fd4c4022b0aed9fe5a6f8069575b506c89 Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:33:09 +0900
Subject: [PATCH 18/21] comment on why older version in ci

---
 .github/workflows/test.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 66f32da..8dbc3fa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -45,6 +45,8 @@ jobs:
             otp: 27.3.1
             clickhouse: 24.12.2.29
             timezone: UTC
+          # some older pre-JSON ClickHouse version
+          # https://github.com/plausible/ch/issues/273
           - elixir: 1.18
             otp: 28
             clickhouse: 24.5.4.49

From 27e11d8b0a9246b1c53106c2d0749ff6c3f6d5a2 Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 09:34:30 +0900
Subject: [PATCH 19/21] shorter cache key

---
 .github/workflows/test.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8dbc3fa..f2e1dd7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -80,10 +80,10 @@ jobs:
           path: |
             deps
             _build
-          key: test-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ github.head_ref || github.ref }}-${{ hashFiles('**/mix.lock') }}
+          key: test-${{ steps.beam.outputs.elixir-version }}-${{ github.head_ref || github.ref }}-${{ hashFiles('**/mix.lock') }}
           restore-keys: |
-            test-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-${{ github.head_ref || github.ref }}-
-            test-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-refs/heads/master-
+            test-${{ steps.beam.outputs.elixir-version }}-${{ github.head_ref || github.ref }}-
+            test-${{ steps.beam.outputs.elixir-version }}-refs/heads/master-
 
       - run: mix deps.get --only $MIX_ENV
       - run: mix compile --warnings-as-errors

From 116322b9fd077cba2c21c107c6af133b3dd13c03 Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 14:47:22 +0900
Subject: [PATCH 20/21] fix internal type ordering in Variant (#275)

* fix internal type ordering in Variant

* cleanup

* link pr
---
 CHANGELOG.md             |  4 ++++
 lib/ch/types.ex          |  2 +-
 test/ch/variant_test.exs | 18 ++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 88b6a72..ba42b84 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+- fix internal type ordering in Variant https://github.com/plausible/ch/pull/275
+
 ## 0.5.5 (2025-08-26)
 
 - fix version check for adding JSON settings https://github.com/plausible/ch/pull/274
diff --git a/lib/ch/types.ex b/lib/ch/types.ex
index de29ba2..e86b16c 100644
--- a/lib/ch/types.ex
+++ b/lib/ch/types.ex
@@ -502,7 +502,7 @@ defmodule Ch.Types do
   defp named_columns_to_types([], acc), do: acc
 
   defp build_variant(types) do
-    Enum.sort_by(types, &__MODULE__.encode/1)
+    Enum.sort_by(types, fn t -> IO.iodata_to_binary(encode(t)) end)
   end
 
   # TODO '', \'
diff --git a/test/ch/variant_test.exs b/test/ch/variant_test.exs
index 04b5d8e..23a2c57 100644
--- a/test/ch/variant_test.exs
+++ b/test/ch/variant_test.exs
@@ -19,6 +19,24 @@ defmodule Ch.VariantTest do
              [["Hello, World!"]]
   end
 
+  # https://github.com/plausible/ch/issues/272
+  test "ordering internal types", %{conn: conn} do
+    test = %{
+      "'hello'" => "hello",
+      "-10" => -10,
+      "true" => true,
+      "map('hello', null::Nullable(String))" => %{"hello" => nil},
+      "map('hello', 'world'::Nullable(String))" => %{"hello" => "world"}
+    }
+
+    for {value, expected} <- test do
+      assert Ch.query!(
+               conn,
+               "select #{value}::Variant(String, Int32, Bool, Map(String, Nullable(String)))"
+             ).rows == [[expected]]
+    end
+  end
+
   test "with a table", %{conn: conn} do
     # https://clickhouse.com/docs/sql-reference/data-types/variant#creating-variant
     Ch.query!(conn, """

From d8cb624409678529dd9ca8839cd96d5baefd0ccc Mon Sep 17 00:00:00 2001
From: ruslandoga <ruslandoga+gh@icloud.com>
Date: Tue, 26 Aug 2025 14:48:11 +0900
Subject: [PATCH 21/21] release v0.5.6

---
 CHANGELOG.md | 2 +-
 mix.exs      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba42b84..75810b0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## Unreleased
+## 0.5.6 (2025-08-26)
 
 - fix internal type ordering in Variant https://github.com/plausible/ch/pull/275
 
diff --git a/mix.exs b/mix.exs
index e0dc05c..4f86353 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,7 +2,7 @@ defmodule Ch.MixProject do
   use Mix.Project
 
   @source_url "https://github.com/plausible/ch"
-  @version "0.5.5"
+  @version "0.5.6"
 
   def project do
     [