How to add custom default value to Nullable type when creating table in clickhouse?

Question

I want to be able to insert null values for specific rows, not by default For example: I hope to be able to insert null values for age, but if not specified then it's defaulted with the value 10.

create table mytable
        (
            age Int null default 10,
            name String
            
        ) ENGINE = MergeTree()
        ORDER BY name

result

Code: 62, e.displayText() = DB::Exception: Syntax error: failed at position 88 ('default') (line 3, col 26): default 10,
            name String
            
        ) ENGINE = MergeTree()
        ORDER BY name. Expected one of: CODEC, TTL, ClosingRoundBracket, Comma, COMMENT, token (version 21.8.10.19 (official build))

the documentation says: NULL is the default value for any Nullable type, unless specified otherwise in the ClickHouse server configuration.

I think I have to find the correct setting on this page or I misunderstood the relationship between default values and Nullable type...

Answer 1

ClickHouse has a special syntax Nullable( <type> ) --> age Nullable(Int)

create table mytable
        (
            age Nullable(Int) default 10,
            name String
            
        ) ENGINE = MergeTree()
        ORDER BY name