There are many times when the data files you receive will have no field values. In the data modeling world when a field is missing it value we say that it's value is NULL.
There are times when you don't care and you simply let it remain NULL. There are other times when your end users have no clue what the displayed "-" symbol means so you want to do something with those NULL field values.
There are lots of ways to handle them, but I'm not the kind of guy that likes putting a whole bunch of IF THEN logic in place to test. The authors probably had a larger audience in mind than just myself, but I sure do love the solution. You simply have to identify the fields that you want to have NULL's replaced for and what you want the NULL value to be replaced by.
This video demonstrates that you can set the NULL values to either numeric values or textual values. Just depends on your situations. Now that's a quick solution to filling in missing field values until you solve the problem of getting data sets with NULL values.