ALTER TYPE¶

Modifies the properties for an existing user-defined type.

See also:: CREATE TYPE , DESCRIBE TYPE , SHOW TYPES , DROP TYPE , UNDROP TYPE

Syntax¶

ALTER TYPE [ IF EXISTS ] <name> SET
  COMMENT = '<string_literal>'

ALTER TYPE [ IF EXISTS ] <name> UNSET COMMENT

Parameters¶

name

Specifies the identifier for the user-defined type to alter.

If the identifier contains spaces or special characters, the entire string must be enclosed in double quotes. Identifiers enclosed in double quotes are also case-sensitive.

For more information, see Identifier requirements.

SET ...

Specifies the properties to set for the user-defined type:

COMMENT = 'string_literal': Adds a comment or overwrites an existing comment for the user-defined type.

UNSET ...

Specifies the properties to unset for the user-defined type, which resets them to the defaults.

Currently, the only property you can unset is COMMENT, which removes the comment, if one exists, for the user-defined type.

Access control requirements¶

A role used to execute this operation must have the following privileges at a minimum:

Privilege	Object	Notes
OWNERSHIP	User-defined type	OWNERSHIP is a special privilege on an object that is automatically granted to the role that created the object, but can also be transferred using the [GRANT OWNERSHIP](/sql-reference/sql/grant-ownership) command to a different role by the owning role (or any role with the MANAGE GRANTS privilege).

Operating on an object in a schema requires at least one privilege on the parent database and at least one privilege on the parent schema.

For instructions on creating a custom role with a specified set of privileges, see Creating custom roles.

For general information about roles and privilege grants for performing SQL actions on securable objects, see Overview of Access Control.

Usage notes¶

Regarding metadata:

Attention

Customers should ensure that no personal data (other than for a User object), sensitive data, export-controlled data, or other regulated data is entered as metadata when using the Snowflake service. For more information, see Metadata fields in Snowflake.

Examples¶

Add a comment to the age user-defined type:

ALTER TYPE age SET COMMENT = 'User-defined type for storing age values';

Remove the comment from the age user-defined type:

ALTER TYPE age UNSET COMMENT;