Update first empty column from an array of columns? Expression help

[MotionMan]

Hello everyone,

My problem is -

I have a list in SharePoint which is technically a "Course" list, and a row basically makes a course that a trainer is hosting.

I want people to be able to sign up to and be loaded into that Row, within columns "Attendee 1", "Attendee 2", "Attendee 3".

I have separate methods for retrieving my attendees, including an approval flow etc. (They're a Get Items value) .

I've tried my basic approach of If attendee 1 = Empty then update item... If not - - If attendee 2 = empty then update item... However i quickly ran into a wall which tells me I simply can't use update item more than 5 times.

I'm wondering if there's an expression I could use which would achieve the same outcome? So it would basically say check columns (Attendee 1... 12), find the first one that's empty and update that item, if none of them are empty then... (whatever I choose to do).

Am I mad, is this achievable?

Many Thanks in advance for your thoughts.

[v-bacao-msft]

Hi @MotionMan,

Could you tell me what is the purpose of checking if these fields are empty?

And I am afraid that I don't understand why you have to check if it is empty one by one.

I try to use Expression according to your ideas, it seems that can't do what you want.

Maybe try to start with the fundamental needs, use other methods to achieve your needs.

Please provide another more details about your requirements.

Best Regards,

Barry