I need an expression to validate if an ID is already registered in the table

[pablo_minyana]

I have a table called "Assets" which contains a column called "ID_Asset".

I need to set a "valid if" that will not allow me to create a record if that "ID_Asset" already exists in the table.

I can not mark it as key, as it is another column in the table.

Greetings!

[diogolupcosta]

IN() 

[dbaum]

How to Prevent Duplicate Records - Google Cloud Community  

BTW, questions like this should be posted in the Q&A board, where they're more likely to be seen by someone who can provide an answer and won't confuse anyone reviewing this Tips board for the type of content it's intended for. I suggested to moderators that they move the post.