And i have such a situation that someone is updating item "Mark" with id=2 to another name. The new name he writes is "Tom". But the column name must be unique in that table. So i need to write trigger (pre-update i think) that would return back a value "Mark" to a field with ID=2 when user updating that field enters name "Tom" and presses save or cursor leaves the item.
How could i do so?