Sum columns with null values in oracle

Question

I want to add two numbers together but when one of those numbers is null then the result is null. Is there a way around this. I could simply do it in the code but I would

Answer 1

Without group by SUM(NVL(regular, 0) + NVL(overtime, 0)) will thrown an error and to avoid this we can simply use NVL(regular, 0) + NVL(overtime, 0)