A plpython solution is available in Issue #66 of PostgreSQL GeneralBits.
http://www.varlena.com/GeneralBits/66
Let me know if this helps.
elein
On Mon, Apr 05, 2004 at 01:01:39PM -0400, Gavin wrote:
> Hi All, I have been tinkering with a function to log the changes made on
> any column through a function and trigger. However, I cant think of a way
> to make this work through pl/pgsql. Any one have any ideas, or is it just
> not possible?
>
> SNIP
> create or replace function logchange2() returns OPAQUE as '
> DECLARE
> columnname record;
> c2 VARCHAR(64);
>
> BEGIN
>
> /* Cycle through the column names so we can find the changes being made */
> FOR columnname IN SELECT attname FROM pg_attribute, pg_type
> WHERE attnum > 0 AND typrelid=attrelid AND typname=''SOMETABLE'' LOOP
>
> c2 := CAST(columnname.attname AS VARCHAR(64));
> /* here lies the problem. How would I make plpgsql see OLD.columnname in
> a dynamic fashion. I know this wont work whats below, but I am just
> trying to express what I am trying to do */
> IF ''OLD.'' || c2 != ''NEW.'' || c2 THEN
> /* IF CHANGED DO SOMETHING */
> RAISE NOTICE ''Update on column %'', c2;
> END IF;
>
> END LOOP;
>
> return NULL;
> END;
> '
> LANGUAGE plpgsql;
>
> create trigger logchange2 AFTER UPDATE on TABLENAME FOR EACH ROW EXECUTE
> PROCEDURE logchange2();
>
>
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