Hi there,
i'm using the following trigger function to update a timestamp of a row when
it is UPDATEd:
CREATE OR REPLACE modified_trigger() RETURNS opaque AS $$
BEGIN
NEW.modify_timestamp := now();
END;
$$ LANGUAGE SQL;
Since i like to use the same trigger for various tables, i'm planning to
keep it very generic.
What i'd like to do now is to just update the modify_timestamp column if OLD
and NEW are different. I'd LOOP over the row elements, and compare each
column of OLD with NEW, and bailing out if there's a difference.
I'd appreciate your help on the following two questions:
- How can i get the column names of NEW/OLD? Is there a set returning
function for this?
- Is there a more efficient way to compare whole rows?
thanks,
Alex Mayrhofer
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