**Use case**

```
Received exception from server (version 21.11.1):
Code: 36. DB::Exception: Received from localhost:9000. DB::Exception: Wrong index name. Cannot find index `test_pentagram` to drop.. (BAD_ARGUMENTS)

github-explorer.ru-central1.internal :) ALTER TABLE hackernews DROP INDEX text_pentagram
```

It did not show me the typo.
command.column_name = getIdentifierName(command_ast->column);
        const auto & ast_comment = command_ast->comment->as<ASTLiteral &>();
        command.comment = ast_comment.value.get<String>();
        command.if_exists = command_ast->if_exists;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::MODIFY_COMMENT)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = COMMENT_TABLE;
        const auto & ast_comment = command_ast->comment->as<ASTLiteral &>();
        command.comment = ast_comment.value.get<String>();
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::MODIFY_ORDER_BY)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = AlterCommand::MODIFY_ORDER_BY;
        command.order_by = command_ast->order_by;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::MODIFY_SAMPLE_BY)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = AlterCommand::MODIFY_SAMPLE_BY;
        command.sample_by = command_ast->sample_by;
        return command;