Question

I would like to replace the all digits in a number with *, other than the last 4.

Here is my table:

Person
-----------
PersonID PersonBadgeNumber numeric(16,0)

Answer 1

Another method is to use STUFF():

DECLARE @n numeric (16, 0);
SET @n = 1234567890123456;
SELECT STUFF(@n, 1, LEN(@n) - 4, REPLICATE('*', LEN(@n) - 4))

The above returns:

---------------- 
************3456