append field contents in patch

[Anonymous]

So hopefully I'm just missing something obvious here and it's an easy ask:

I want to patch a collection using data that's already in the collection - kind of like an append-to function for a specific field so;

ForAll(Collection1, Patch(Collection2, Record, {datafield: datafield & "more data"}))

I can't seem to access what's currently there inside the Patch statement for that field - it just says "invalid name".

Am I going about this all wrong?

Kind regards,

Russel

[Anonymous · Accepted solution]

Nevermind - found it 

ForAll(Collection1, Patch(Collection2, Record, {datafield: LookUp(Collection2, condition).datafield & "more data"}))