How change TextBox to TextArea field?

Hello. How can I change text box field to text area? I have to edit database?Thanks.

Feature request:
Please make ability in backend to change field type (JomSocial has it):
Textbox <-> Textarea.
Radiobix -> Checkbox / List.
etc.

Also please make: If I delete “FIELD_MOVIE (textbox)” and create “FIELD_MOVIE (textarea)”, data that was filled in textbox before will be displaying in textarea.

Thanks.