I have read the CB 1.4 documentation, look at the FAQs and tried to search these Forums and was unable to find the answer to this question. In the Advanced user search in the CB back-end, how do you search for an empty or NULL field?
in SQL I would say WHERE lastname IS NULL
or WHERE lastname LIKE ''
I tried using <field> 'is exactly' and leaving the value field blank, but that matches everything.