Question

I have a table assoc containing columns

local_id, remote_id, cachedData

I can successfully run an SQLITE query that looks like

SELECT a1.local_id, a1.remote_id FROM assoc a1 LEFT JOIN ....

so that I identify certain rows of the assoc table that meet my criteria.

What I would like to do is to set cachedData to null in those rows.

How can I do this? Sqlite doesn’t support UPDATE with joins; you can issue subqueries but I can’t figure out how to get the syntax correct; it seems nonintuitive to me.

Answer 1

 UPDATE assoc SET cachedData = NULL
    WHERE EXISTS (SELECT * FROM otherTable 
        WHERE otherTable.Col1 = assoc.Col1 AND otherTable.Col2 = assoc.Col1)

Be aware that this is not especially performant.