eh?

lib/ch/row_binary.ex

@@ -516,6 +516,7 @@ defmodule Ch.RowBinary do
               :uuid,
               :date,
               :date32,
+              :json,
               :ipv4,
               :ipv6,
               :point,
@@ -865,6 +866,9 @@ defmodule Ch.RowBinary do
         <<d::32-little-signed, bin::bytes>> = bin
         decode_rows(types_rest, bin, [Date.add(@epoch_date, d) | row], rows, types)
 
+      :json ->
+        raise ArgumentError, "JSON type is not supported for decoding: #{inspect(bin)}"
+
       {:datetime, timezone} ->
         <<s::32-little, bin::bytes>> = bin
 

lib/ch/types.ex

@@ -26,6 +26,7 @@ defmodule Ch.Types do
       # {"DateTime", :datetime, []},
       {"Date32", :date32, []},
       {"Date", :date, []},
+      {"JSON", :json, []},
       {"LowCardinality", :low_cardinality, [:type]},
       for size <- [32, 64, 128, 256] do
         {"Decimal#{size}", :"decimal#{size}", [:int]}

test/ch/connection_test.exs

@@ -572,23 +572,39 @@ defmodule Ch.ConnectionTest do
     # https://clickhouse.com/docs/en/integrations/data-formats/json/overview
     # https://clickhouse.com/blog/a-new-powerful-json-data-type-for-clickhouse
     # https://clickhouse.com/blog/json-bench-clickhouse-vs-mongodb-elasticsearch-duckdb-postgresql
+    # https://github.com/ClickHouse/ClickHouse/pull/70288
+    # https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/TypeId.h
     test "json", %{conn: conn} do
       settings = [enable_json_type: 1]
 
-      Ch.query!(conn, "CREATE TABLE test_json(json JSON) ENGINE = Memory", [], settings: settings)
+      assert Ch.query!(
+               conn,
+               ~s|select '{"a":42,"b":10}'::JSON|,
+               [],
+               settings: settings,
+               decode: false,
+               format: "RowBinary"
+             ).rows == [
+               <<2, 1, 97, 10, 42, 0, 0, 0, 0, 0, 0, 0, 1, 98, 10, 10, 0, 0, 0, 0, 0, 0, 0>>
+             ]
 
-      Ch.query!(
-        conn,
-        ~s|INSERT INTO test_json VALUES ('{"a" : {"b" : 42}, "c" : [1, 2, 3]}'), ('{"f" : "Hello, World!"}'), ('{"a" : {"b" : 43, "e" : 10}, "c" : [4, 5, 6]}')|
-      )
+      # Ch.query!(conn, "CREATE TABLE test_json(json JSON) ENGINE = Memory", [], settings: settings)
 
-      assert Ch.query!(conn, "SELECT json FROM test_json") == :asdf
+      # Ch.query!(
+      #   conn,
+      #   ~s|INSERT INTO test_json VALUES ('{"a" : {"b" : 42}, "c" : [1, 2, 3]}'), ('{"f" : "Hello, World!"}'), ('{"a" : {"b" : 43, "e" : 10}, "c" : [4, 5, 6]}')|
+      # )
 
-      assert Ch.query!(conn, "SELECT json.a, json.b.c, json.b.d[3] FROM test_json").rows == [
-               [1, 2, 3]
-             ]
+      # assert Ch.query!(conn, "SELECT json FROM test_json") == :asdf
+
+      # assert Ch.query!(conn, "SELECT json.a, json.b.c, json.b.d[3] FROM test_json").rows == [
+      #          [1, 2, 3]
+      #        ]
     end
 
+    # TODO variant (is there?)
+    # TODO dynamic
+
     # TODO enum16
 
     test "enum8", %{conn: conn} do