Append data with Update Record, how to deal with empty existing data and FLATTEN tokens?

Safest pattern is to put the new value first, then the existing. This avoids issues when the existing field is empty and you'd otherwise start with a dangling comma.

For FLATTEN, most of the problems come from how values are joined afterwards rather than FLATTEN itself. In many cases you can skip it and let Airtable handle the array directly, or just be consistent with your delimiter when combining.

Also worth checking the field type, as whilst this works fine for text fields, linked record fields need a full list of record IDs each time, not appended strings.

Thank you ​@Holly Nilson-Clay!

New value first, check. Makes easy sense.

My current situation is with linked records, as I add new events and tags to a contact (that may or may not have them from before). In that case, what do you mean with “full list of record IDs each time, not appended strings.”? 

Cheers!

Björn

So, with linked record fields, Airtable replaces/overwrites whatever's in the field with whatever you pass in the update step. It doesn’t just add to what is already there. So if a contact already has 3 tags and you try to add in 1 new one, you’ll end up with just the 1 new one and the original 3 will disappear.

To avoid that, you need to pass the existing linked record IDs plus the new one together in the same update step. Usually, that means pulling the current linked records from a previous step, then combining those IDs with the new one before writing back. Does that make sense?

​@Holly Nilson-Clay, I may not have been clear. I have this already in the same step, that’s the only way I have thought these could work. So, is there then something special to consider regarding linked records?

Björn