SQL: sum 3 columns when one column has a null value?

Question

SELECT 
    sum(TotalHoursM)
          + (TotalHoursT)
          + (TotalHoursW)
          + (TotalHoursTH)
          + (TotalHoursF) 
          AS TOTAL
FROM LeaveR         


        

Answer 1

If you want to avoid the null value use IsNull(Column, 1)

Answer 2

You can also use nvl(Column,0)

Answer 3

You can use ISNULL:

ISNULL(field, VALUEINCASEOFNULL)