Android Question How to read a null value from db?

It often happens to read lines from a db where some fields are null
Attempting to add a row to a FlexGrid when a field is null invalidates the entire row insert operation
The question is: how to read db fields whose content is null without creating problems for subsequent instructions?
Is the only way the classic comparison via IF or are there any tricks to protect the reading of db fields and prevent a Null from being returned?