Quick question about IDs

[dunhill]

I have custom identifiers in ids and thanks to the help of the people on the forum I was able to create a custom column that, depending on another one called library (destination), I get the identifier.
So that it is understood, to know the Amazon identifier
In the book's bookstore field, if I put Amazon, it brings me the Amazon identifier in another column with the name isbn.

In case it helps you at all

With this template:

program:
switch_if(
$#library == 'Yenny', select($identifiers, 'yenny'),
$#library == 'Cúspide', select($identifiers, 'cuspide'),
$#library == 'Amazon', select($identifiers, 'amazon'),
$#library == 'Kindle Unlimited', select($identifiers, 'ku'),
'')