Compare two tables and flag divergent records

[-dp-]

I have an InstalledApp table that contains a list of apps installed on student iPads. I have an ApprovedApp table, which is a list of all apps that have been approved by the administration. I need for InstalledApp::appUnapproved to be populated with “Unapproved” in every record where InstalledApp::appName does not occur in the ApprovedApp table. I can probably script this with nested loops, but wonder if a calculation guru can suggest a more efficient method. Thanks.
 

[comment]

Assuming that the 2 tables are related by appName, you could do simply (result is Text):

If ( IsEmpty ( ApprovedApp::appName ) ; "Unapproved" )

 

Personally, I would prefer to make the result Number and use only:

IsEmpty ( ApprovedApp::appName )

but Filemaker limits the length of the string you can display when formatting a field as Boolean to 7 characters.

 

Edited August 16, 2023 by comment

[-dp-]

Understood. Thank you for your help.