In MS Access, I have a table linked to an external Excel file. In that table I have three numerical columns. In MS Access I have a query that uses those 3 columns and adds a fourth field which is the sum of all three columns.
Here is my problem: it only works as expected when there is data in all three columns. If even one of the columns has a blank in it, then the sum field I added shows a zero.
How can I fix this?