In that case, you must define a key field, so that Ninox can detect which records are going to be updated. Select ‘Key’ for this field instead of ‘Update all’. Key fields must be unique, that is, there must not be two data records in the table / CSV file where this field has the same value. It is possible to define more than one key field to assure unambiguity (e.g. ‘first name’ and ‘last name’ of one person).