Alter Standard Table - Comment

Last updated: January 27, 2026

Modifies or removes the table comment.

Known limitations:

This change type does not support automatic rollback.
Snowflake snapshots created with Liquibase Secure 5.1 are incompatible with earlier versions due to enhanced object type detection for TABLES and VIEWS. Regenerate all snapshots with 5.1 after upgrading to avoid false differences in diff and diff-changelog operations.

Available attributes

Attribute	Type	Description	Required
`catalogName`	String	Name of the catalog (database) containing the table	No
`schemaName`	String	Name of the schema containing the table	No
`tableName`	String	Name of the table to alter	Yes
`ifExists`	Boolean	Only execute if the table exists	No

alterComment nested attributes

Attribute	Type	Description	Required
`newComment`	String	New comment text	No*
`unsetComment`	Boolean	If true, removes the comment	No*

*Exactly one of newComment or unsetComment must be specified.

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
        xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
        xmlns:pro-snowflake="http://www.liquibase.org/xml/ns/pro-snowflake"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
        http://www.liquibase.org/xml/ns/pro-snowflake
        http://www.liquibase.org/xml/ns/pro-snowflake/liquibase-pro-snowflake-latest.xsd">

    <!-- Set comment -->
    <changeSet id="update-comment" author="examples">
        <pro-snowflake:alterStandardTable tableName="MY_TABLE">
            <pro-snowflake:alterComment newComment="Updated table description"/>
        </pro-snowflake:alterStandardTable>
    </changeSet>

    <!-- Remove comment -->
    <changeSet id="remove-comment" author="examples">
        <pro-snowflake:alterStandardTable tableName="MY_TABLE">
            <pro-snowflake:alterComment unsetComment="true"/>
        </pro-snowflake:alterStandardTable>
    </changeSet>

</databaseChangeLog>

{
  "databaseChangeLog": [
    {
      "changeSet": {
        "id": "update-comment",
        "author": "examples",
        "changes": [
          {
            "alterStandardTable": {
              "tableName": "MY_TABLE",
              "alterComment": {
                "newComment": "Updated table description"
              }
            }
          }
        ]
      }
    },
    {
      "changeSet": {
        "id": "remove-comment",
        "author": "examples",
        "changes": [
          {
            "alterStandardTable": {
              "tableName": "MY_TABLE",
              "alterComment": {
                "unsetComment": true
              }
            }
          }
        ]
      }
    }
  ]
}

databaseChangeLog:
  # Set comment
  - changeSet:
      id: update-comment
      author: examples
      changes:
        - alterStandardTable:
            tableName: MY_TABLE
            alterComment:
              newComment: "Updated table description"

  # Remove comment
  - changeSet:
      id: remove-comment
      author: examples
      changes:
        - alterStandardTable:
            tableName: MY_TABLE
            alterComment:
              unsetComment: true

--liquibase formatted sql

--changeset examples:set-comment
-- Set comment
ALTER TABLE MYDB.PUBLIC.MY_TABLE SET COMMENT = 'Updated table description';

--changeset examples:remove-comment
-- Remove comment
ALTER TABLE MYDB.PUBLIC.MY_TABLE UNSET COMMENT;

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
        xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
        xmlns:pro-snowflake="http://www.liquibase.org/xml/ns/pro-snowflake"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
        http://www.liquibase.org/xml/ns/pro-snowflake
        http://www.liquibase.org/xml/ns/pro-snowflake/liquibase-pro-snowflake-latest.xsd">

    <!-- Set comment -->
    <changeSet id="update-comment" author="examples">
        <pro-snowflake:alterStandardTable tableName="MY_TABLE">
            <pro-snowflake:alterComment newComment="Updated table description"/>
        </pro-snowflake:alterStandardTable>
    </changeSet>

    <!-- Remove comment -->
    <changeSet id="remove-comment" author="examples">
        <pro-snowflake:alterStandardTable tableName="MY_TABLE">
            <pro-snowflake:alterComment unsetComment="true"/>
        </pro-snowflake:alterStandardTable>
    </changeSet>

</databaseChangeLog>

{
  "databaseChangeLog": [
    {
      "changeSet": {
        "id": "update-comment",
        "author": "examples",
        "changes": [
          {
            "alterStandardTable": {
              "tableName": "MY_TABLE",
              "alterComment": {
                "newComment": "Updated table description"
              }
            }
          }
        ]
      }
    },
    {
      "changeSet": {
        "id": "remove-comment",
        "author": "examples",
        "changes": [
          {
            "alterStandardTable": {
              "tableName": "MY_TABLE",
              "alterComment": {
                "unsetComment": true
              }
            }
          }
        ]
      }
    }
  ]
}

databaseChangeLog:
  # Set comment
  - changeSet:
      id: update-comment
      author: examples
      changes:
        - alterStandardTable:
            tableName: MY_TABLE
            alterComment:
              newComment: "Updated table description"

  # Remove comment
  - changeSet:
      id: remove-comment
      author: examples
      changes:
        - alterStandardTable:
            tableName: MY_TABLE
            alterComment:
              unsetComment: true

--liquibase formatted sql

--changeset examples:set-comment
-- Set comment
ALTER TABLE MYDB.PUBLIC.MY_TABLE SET COMMENT = 'Updated table description';

--changeset examples:remove-comment
-- Remove comment
ALTER TABLE MYDB.PUBLIC.MY_TABLE UNSET COMMENT;

Alter Standard Table - Comment

Available attributes

alterComment nested attributes

XML

JSON

YAML

SQL

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