Fixed tuples

Author: chernser

client-v2/src/main/java/com/clickhouse/client/api/data_formats/JSONEachRowFormatReader.java

@@ -429,7 +429,14 @@ public Object[] getTuple(int index) {
 
     @Override
     public Object[] getTuple(String colName) {
-        return (Object[]) currentRow.get(colName);
+        Object value = currentRow.get(colName);
+        if (value == null) {
+            return null;
+        }
+        if (value instanceof List<?>) {
+            return ((List<?>) value).toArray(new Object[0]);
+        }
+        return (Object[]) value;
     }
 
     @Override

client-v2/src/test/java/com/clickhouse/client/api/data_formats/JSONEachRowFormatReaderTest.java

@@ -401,7 +401,8 @@ public void testUuidAndListAccessors() throws Exception {
         UUID uuid = UUID.fromString("11111111-2222-3333-4444-555555555555");
         try (JSONEachRowFormatReader reader = readerOf(row(
                 "u", uuid.toString(),
-                "arr", Arrays.asList(1, 2, 3)))) {
+                "arr", Arrays.asList(1, 2, 3),
+                "tuple", Arrays.asList("a", 1)))) {
             reader.next();
 
             Assert.assertEquals(reader.getUUID("u"), uuid);
@@ -410,6 +411,9 @@ public void testUuidAndListAccessors() throws Exception {
             List<Integer> list = reader.getList("arr");
             Assert.assertEquals(list, Arrays.asList(1, 2, 3));
             Assert.assertEquals(reader.<Integer>getList(2), Arrays.asList(1, 2, 3));
+
+            Assert.assertEquals(reader.getTuple("tuple"), new Object[] {"a", 1});
+            Assert.assertEquals(reader.getTuple(3), new Object[] {"a", 1});
         }
     }
 

docs/client-v2-json-support.md

@@ -311,6 +311,13 @@ Behavior:
   the `List` implementation produced by the selected JSON library. Because
   `JSONEachRow` has no array element metadata, `ResultSet.getArray(...)` is
   not supported for these inferred JSON arrays.
+- Temporal typed JDBC accessors follow the current `JSONEachRowFormatReader`
+  text-accessor support. `ResultSet.getString(...)` can be used to read the
+  server-formatted temporal text, but `getTimestamp(...)`,
+  `getObject(..., Timestamp.class)`, and related temporal conversions are not
+  guaranteed for `FORMAT JSONEachRow` result sets. Use the binary default
+  format when JDBC temporal typed accessors are required, or read the value as
+  a string/object and convert it in application code.
 - The JSON processor is selected at the connection level through the
   `jdbc_json_parser_factory` driver property. It cannot be changed per
   statement, in line with the lifecycle of other connection options.

docs/features.md

@@ -80,7 +80,7 @@ Compatibility-sensitive traits:
 - String-like ClickHouse values have stable JDBC expectations: `String`, `FixedString`, and `Enum` values are returned as strings, while `UUID` is available both as `getString()` and `getObject(..., UUID.class)`.
 - `Geometry` has a stable JDBC mapping: metadata reports SQL type `ARRAY` with type name `Geometry`, read paths return nested Java arrays rather than custom wrappers, and write paths depend on the caller preserving the intended point/array nesting shape.
 - JDBC `Geometry` writes share the same ambiguity as the client serializer: variant selection is inferred from nesting depth, so `Ring` versus `LineString` and `Polygon` versus `MultiLineString` are not currently distinguishable when writing through the generic `Geometry` path.
-- JDBC `FORMAT JSONEachRow` support is opt-in through the `jdbc_json_parser_factory` driver property, whose value must be a fully-qualified `JsonParserFactory` class name with a public no-argument constructor; JSONEachRow numeric and structured value behavior follows the selected parser and configured server output settings. Inferred JSON arrays are returned from `ResultSet.getObject(...)` as parser-native `List` values rather than JDBC `Array` values because JSONEachRow does not include element metadata.
+- JDBC `FORMAT JSONEachRow` support is opt-in through the `jdbc_json_parser_factory` driver property, whose value must be a fully-qualified `JsonParserFactory` class name with a public no-argument constructor; JSONEachRow numeric and structured value behavior follows the selected parser and configured server output settings. Inferred JSON arrays are returned from `ResultSet.getObject(...)` as parser-native `List` values rather than JDBC `Array` values because JSONEachRow does not include element metadata. JDBC temporal typed accessors such as `getTimestamp(...)` are not guaranteed for JSONEachRow result sets; callers that need stable JDBC temporal conversions should use the binary default format or perform application-level conversion from string/object values.
 - Binary parameters passed through `setBytes()` are encoded as ClickHouse `unhex(...)` expressions rather than text literals; empty byte arrays map to an empty string expression.
 - Stream and reader setters (`setAsciiStream`, `setUnicodeStream`, `setBinaryStream`, `setCharacterStream`, `setNCharacterStream`) are treated as text input encoded with the same string-escaping rules, including length-based truncation when a length is supplied.
 - `getString()` formatting for temporal values is stable output: `Date` uses `yyyy-MM-dd`, `DateTime` uses `yyyy-MM-dd HH:mm:ss`, and `DateTime64` preserves fractional precision, all interpreted in server timezone context where applicable.