Updated on 2025-04-21 GMT+08:00

ADD COLUMNS

Function

The ADD COLUMNS command is used to add a column to an existing table.

Syntax

ALTER TABLE Table name ADD COLUMNS(col_spec[, col_spec ...])

Parameter Description

**Table 1** ADD COLUMNS parameters
Parameter	Description
tableName	Table name.
col_spec	Column specifications, consisting of four fields, col_name, col_type, nullable, and comment. col_name: name of the new column. It is mandatory. Adding new subcolumns to nested columns is currently not supported. col_type: type of the new column. It is mandatory. nullable: whether the new column can be null. The value can be left empty. comment: comment of the new column. The value can be left empty.

Required Permissions

SQL permissions

**Table 2** Permissions required for executing ALTER TABLE
Permission Description
ALTER permission on a table

Fine-grained permission: dli:table:alter

Metadata services provided by LakeFormation. Refer to the LakeFormation documentation for details on permission configuration.

Example

alter table h0 add columns(ext0 string);

alter table h0 add columns(new_col int comment 'add new column');

alter table delta.`obs://bucket_name0/db0/delta_table0` add columns(new_col string);

Response

You can run the DESCRIBE command to view the new column.

Parent topic: Schema Evolution Syntax