Modifying Column Comments

Updated on 2024-08-19 GMT+08:00

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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';

**Table 1** Parameters
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.

    
       ALTER TABLE t1 CHANGE COLUMN c1 c1 STRING COMMENT 'the new comment';

Parent topic: Modifying a Table

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