question on calculation

for calculation trying to build "total bill" I need it to be column A + column B + column C, but there are  times when column C is null, if I write it as column A + B + C only the rows with a value in C will fill in

 

how would I do this calculation for both cases?

 

 

thank you

Comments

  • You can do

    SUM(IFNULL(`ColumnA`,0), IFNULL(`ColumnB`,0), IFNULL(`ColumnC`,0)) 
  • makes sense, when I add the calculation to my card though am getting

     

    "an issue occurred during processing. We are unable to complete request at this time"

  • Other than Nulls in your fields , is there anything else that could be forcing the field to be a Text field instead of numeric ?  spaces at the end or beggining , maybe a humman error inputing a letter instead of a number etc  ?