# ALTER TABLE ADD COLUMNS
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Adds one or more columns to an existing Iceberg table.

## Synopsis
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```
ALTER TABLE [db_name.]table_name ADD COLUMNS (col_name data_type [,...])
```

## Examples
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The following example adds a `comment` column of type `string` to an Iceberg table.

```
ALTER TABLE iceberg_table ADD COLUMNS (comment string)
```

The following example adds a `point` column of type `struct` to an Iceberg table.

```
ALTER TABLE iceberg_table 
ADD COLUMNS (point struct<x: double, y: double>)
```

The following example adds a `points` column that is an array of structs to an Iceberg table.

```
ALTER TABLE iceberg_table 
ADD COLUMNS (points array<struct<x: double, y: double>>)
```