Hello,
I want to update columns in a table that match a fixed key
from the same column of the same table matching another fixed key.
There can be several tuples per key distinguished by a secondary id.
Tuples are unique with the combined keys. Maybe a query could look
something like this:
Jurgen,
UPDATE a.mytable from b.mytable
SET a.mycolumn = b.mycolumn
WHERE a.firstid = some_key
AND b.firstid = some_other_key
AND a.secondaryid = b.secondaryid;
Very close, actually; you just need to fix the table alias:
UPDATE mytable
FROM
