Extraction float64 value from JSON fails

[cetver]

Describe the bug
The JSONExtract functions can't extract the float64 value

How to reproduce

SELECT
    JSONExtract(json, 'value', 'String') str,
    JSONExtract(json, 'value', 'Float64') int,
    JSONExtractRaw(json) raw,
    type
FROM (
    SELECT '{"value":99999999999999999999}' json, 'float' type
    UNION ALL
    SELECT '{"value":"99999999999999999999"}' json, 'string' type
);
-- Float64
SELECT toTypeName(99999999999999999999);

• Which ClickHouse server version to use
  20.11.4.13

Expected behavior

ACTUAL

+----------------------+-----+----------------------------------+--------+
| str                  | int | raw                              | type   |
+----------------------+-----+----------------------------------+--------+
|                      | 0   |                                  | float  |
+----------------------+-----+----------------------------------+--------+
| 99999999999999999999 | 0   | {"value":"99999999999999999999"} | string |
+----------------------+-----+----------------------------------+--------+

EXPECTED

+----------------------+----------------------+----------------------------------+--------+
| str                  | int                  | raw                              | type   |
+----------------------+----------------------+----------------------------------+--------+
| 99999999999999999999 | 99999999999999999999 | {"value":99999999999999999999}   | float  |
+----------------------+----------------------+----------------------------------+--------+
| 99999999999999999999 | 0                    | {"value":"99999999999999999999"} | string |
+----------------------+----------------------+----------------------------------+--------+

[tavplubix]

JSON format does not have float64 data type, it has implementation-defined Number data type. The number 99999999999999999999 is not representable as Number in some implementations, so the first row is invalid and JSONExtract returns empty string.

:) SELECT isValidJSON(json), type FROM (SELECT '{"value":99999999999999999999}' json, 'float' type UNION ALL SELECT '{"value":"99999999999999999999"}' json, 'string' type)

SELECT
    isValidJSON(json),
    type
FROM 
(
    SELECT
        '{"value":99999999999999999999}' AS json,
        'float' AS type
    UNION ALL
    SELECT
        '{"value":"99999999999999999999"}' AS json,
        'string' AS type
)

┌─isValidJSON(json)─┬─type──┐
│                 0 │ float │
└───────────────────┴───────┘
┌─isValidJSON(json)─┬─type───┐
│                 1 │ string │
└───────────────────┴────────┘

[cetver]

Thanks for the explanation.

I still think that this is a bug, or the behavior is not specified in the documentation.

Max "true" int is Int64, if the value between -9223372036854775808 : 9223372036854775807 extract functions works as expected

Сonclusion: keep int, float values as string