Is there a way to distinguish between inserted values and values added by clickhouse in JSON type ?

[Derianer]

Hello

Problem is that clickhouse adds fields with values to previously saved objects if I save a new object with additional fields.
For example:

SET allow_experimental_object_type=1;

CREATE TABLE test_json (obj JSON) ENGINE = MergeTree ORDER BY tuple();

INSERT INTO test_json FORMAT JSONEachRow {"obj": {"key1": 1}};

INSERT INTO test_json FORMAT JSONEachRow {"obj": {"key1": 1, "key2": 2}};

SELECT obj FROM test_json FORMAT JSONEachRow SETTINGS output_format_json_named_tuples_as_objects=1;

Output:

{"obj":{"key1":1,"key2":2}}
{"obj":{"key1":1,"key2":0}}

Is there a way to distinguish values that were inserted with the query and values added by clickhouse ? Or maybe there is an option to save such values as NULL?

[avelychko12]

Try to use Object(Nullable('json')) type instead of JSON

[Derianer]

it worked, thanks