Re: How to access NEW or OLD field given only the field's name?

[François Beausoleil <francois@xxxxxxxxxxx>]

Hi,

Le 2014-03-19 à 16:19, Adrian Klaver a écrit :

On 03/19/2014 12:48 PM, François Beausoleil wrote:

Cross-posted from https://dba.stackexchange.com/questions/61271/how-to-access-new-or-old-field-given-only-the-fields-name

Well two things:

1)  From the above link:
Note that parameter symbols can only be used for data values — if you want to use dynamically determined table or column names, you must insert them into the command string textually. For example, if the preceding query needed to be done against a dynamically selected table, you could do this:

Is there an example missing here?

So:

Instead of 'SELECT $1 '.. use 'SELECT ' || TG_ARGV[0] || ..

2) Use NEW outside the quotes.

So:
 'FROM ' NEW.*

That doesn't seem to work?

CREATE OR REPLACE FUNCTION validate_arrays_sum_equals_total() RETURNS TRIGGER AS $$

DECLARE

  total bigint;

  array_sum bigint;

BEGIN

  EXECUTE 'SELECT $1 FROM ' NEW.* INTO total USING TG_ARGV[0];

  RAISE EXCEPTION 'Total: %, social_impressions: %', total, NEW.social_impressions;

  RETURN NEW;

END

$$ LANGUAGE plpgsql;

psql:db/functions.sql:117: ERROR:  syntax error at or near "."

LINE 6:   EXECUTE 'SELECT $1 FROM ' NEW.* INTO total USING TG_ARGV[0...

                                       ^

Thanks,

François

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