I am creating a computed column in a query task of SAS EG 4.1. For the computed column I am subtracting field b from field a, for example (a-b). a has a value of 643 and column b, for this particular row, has a value of null. My result ends up being null instead of 643. How do I get the query task to treat the null as a zero so that my computed column has a resulting value of 643?
As a side note, in some cases column b has a value other than null, so it is only for the calculations where b is equal to null that I need b to be recognized as a 0.