Hi Asghar,
This is not an efficient way of design. Please register their issue date and by computing the DAYs between any date and issue date you can compute the NO_OF_DAYS dynamically.
But about the way you have done it here : What happens if you forget to update the column someday due to some technical problems. And what happens if you update that row multiple times in a day.
If you changed your design use this function to have your NO_OF_DAYS computed :
DATEDIFF[
^] and for getting today date :
GETDATE[
^]
Hope it helps.