You can modify the column comments of non-partitioned or partitioned tables.
ALTER TABLE [db_name.]table_name CHANGE COLUMN col_name col_name col_type COMMENT 'col_comment';
Parameter |
Mandatory |
Description |
|---|---|---|
db_name |
No |
Database name. Only letters, digits, and underscores (_) are allowed. The name cannot contain only digits or start with an underscore (_). |
table_name |
Yes |
Table name |
col_name |
Yes |
Column name. The value must be the name of an existing column. |
col_type |
Yes |
Column data type specified when the table is created, which cannot be modified. |
col_comment |
Yes |
Column comment after modification. The comment can contain a maximum of 1024 bytes. |
Change the comment of the c1 column in the t1 table to the new comment.
1 | ALTER TABLE t1 CHANGE COLUMN c1 c1 STRING COMMENT 'the new comment'; |