How set a field unique on a custom table ... ?

[Zod]

Hi,

I have a custom table extending cmdb_ci.

There is a field (u_....), that I wand to set a unique, but when changing it in the table dictionary, the value will not be saved. No message.

If there are duplicate records, I get the message, that setting unique requires duplicates to be removed first ....   (but when removed .. nothing happens).

THnx

[Zod]

just add a business rule before insert - check if value there allready - if yes abort ... 

Still do not get why this does not seem to work OOB

[Sumit Rathod4]

It seems it is a known issue since a long time.

Please refer below link:

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0657669