

# ALTER TABLE CHANGE COLUMN
<a name="querying-iceberg-alter-table-change-column"></a>

Changes the name, type, order or comment of a column in an Iceberg table.

**Note**  
`ALTER TABLE REPLACE COLUMNS` is not supported. Because `REPLACE COLUMNS` removes all columns and then adds new ones, it is not supported for Iceberg. `CHANGE COLUMN` is the preferred syntax for schema evolution. 

## Synopsis
<a name="querying-iceberg-alter-table-change-column-synopsis"></a>

```
ALTER TABLE [db_name.]table_name
  CHANGE [COLUMN] col_old_name col_new_name column_type 
  [COMMENT col_comment] [FIRST|AFTER column_name]
```

## Example
<a name="querying-iceberg-alter-table-change-column-example"></a>

```
ALTER TABLE iceberg_table CHANGE comment blog_comment string AFTER id
```