Unique Calculated Field?

[mikelski]

I hope there's someone out there who can assist with this. Keeping it simple, I have two related files; Projects - primary key = Project ID and Deliverables - foreign key = Project ID. There is a third unrelated file that will import records from Deliverables, the unique ID being Project ID & "." & Suffix (e.g. 12345.2). It's up to the user to enter the suffix via a portal in Projects, so to prevent duplicates, I created a Calculation field in Deliverables to concatenate the Project ID & "." & Suffix. I was disappointed to discover that there isn't an option to make the result unique, which is a problem. I've tried a variety of workarounds without auccess. Any help is appreciated.

Edited August 12, 2005 by Guest

[CobaltSky]

Hello Mike,

You might get some useful ideas on how to solve this problem from the FileMaker TechInfo article at:

http://filemaker.custhelp.com/cgi-bin/filemaker.cfg/php/enduser/std_adp.php?p_faqid=3483

It requires that you think a little differently about the problem (ie validating the source fields rather than the calc itself) but will get you to where you want to be, I think?! :(

[mikelski]

Hi there - thanks for the link. I created a clean database and followed the instructions to the letter (I think!), however the only way I can produce the custom message on validation failure is to manually enter the value of FullName into the DupCheck field - it doesn't do this itself. I'm not sure if I've set it up incorrectly, or if the solution is flawed. Would you mind having a try yourself?

[CobaltSky]

Mike,

The side-bar says that you're working with FM Dev 6, so I have attached a file created with that version which works straight off (following the instructions in the TechInfo article).

As is stated in the article, the technique is applicable to versions 3 thru 6 of FileMaker, so some variations would be needed if you were looking to implement it in v7. However I assume that is not the case?!

DupCheck.zip

[mikelski]

Thanks for taking the time and trouble to assist me with this, it's very much appreciated. That solution works fine and is just what I'm after.