Clickhouse does not validate DEFAULT value on MODIFY COLUMN for type compability #15854
Description
Describe the bug
Here's my table:
CREATE TABLE table2
(
EventDate Date,
Id Int32,
Value Int32
)
Engine = MergeTree()
PARTITION BY toYYYYMM(EventDate)
ORDER BY Id;Modify default value (intentionally wrong):
>>> alter table table2 modify column Value default 'some_string';
ALTER TABLE table2
MODIFY COLUMN `Value` DEFAULT 'some_string'
Ok.
0 rows in set. Elapsed: 0.007 sec.
Now you obviously cannot insert anything to this table, because:
>>> insert into table2 (EventDate, Id) values (1234567890, 2)
INSERT INTO table2 (EventDate, Id) VALUES
Received exception from server (version 20.9.3):
Code: 6. DB::Exception: Received from localhost:9000. DB::Exception: Cannot parse string 'some_string' as Int32: syntax error at begin of string. Note: there are toInt32OrZero and toInt32OrNull functions, which returns zero/NULL instead of throwing exception..
1 rows in set. Elapsed: 0.002 sec.
How to reproduce
- Which ClickHouse server version to use: 20.9.3
- Which interface to use, if matters: I used standard CLI
Expected behavior
Currently ClickHouse doesn't check types compability while setting a DEFAULT value for a column. Maybe ClickHouse should validate DEFAULT values for type compability?