>>That's wrong way to do it.
>
>Just interested, why do you think so? If the age field is bound to a certain event in time (like age at date of surgery), it does make sense to calculate and store it in a table.

But in this case the event date is NOT stored, so it's the age at any time, presumably the time you look at it (aka now). You can expect that about every three days one percent of the age values would become incorrect.