ALTER TABLE ... MODIFY COMMENT

Adds, modifies, or removes comment to the table, regardless if it was set before or not. Comment change is reflected in both system.tables and SHOW CREATE TABLE query.

Syntax

Examples

Creating a table with comment (for more information, see the COMMENT clause):

Modifying the table comment:

Output of a new comment:

Removing the table comment:

Output of a removed comment:

Caveats

For Replicated tables, the comment can be different on different replicas. Modifying the comment applies to a single replica.

The feature is available since version 23.9. It does not work in previous ClickHouse versions.