How to UPDATE in SQLite using a LEFT JOIN to select candidate rows

Question

I have a table assoc containing columns

local_id, remote_id, cachedData

I can successfully run an SQLITE query that looks like

Answer 1

Aha, there's already a builtin rowid!

UPDATE assoc
SET cachedData=NULL
WHERE rowid IN (
   SELECT rowid FROM assoc a1 LEFT JOIN ...
);