Re: Passing parameters to triggers

Hans-Jürgen Schönig wrote:
> I have a severe problem when working with PL/pgSQL triggers. Somehow the
> problem seems to be strange. Here is the code:
>
> CREATE OR REPLACE FUNCTION checkint () RETURNS opaque AS
> '
>         BEGIN
>                 IF      TG_OP = ''DELETE'' THEN
>                         RAISE NOTICE ''% wert'', TG_ARGV[0];
>                         DELETE FROM TG_ARGV[0];
>                 END IF;
>                 RETURN OLD;
>         END;
> ' LANGUAGE 'plpgsql';
>
> CREATE TRIGGER trig_a_b AFTER DELETE OR UPDATE ON a
>         FOR EACH ROW EXECUTE PROCEDURE checkint('b');
>
> DELETE FROM a;
>
> When running the code I get a strange problem. The RAISE NOTICE command
> works but somehow the DELETE statements displays an error.

    Object  names (tables, attributes, sequences, etc.) cannot be
    parameterized directly in procedural languages.  You can  get
    the wanted result with

        EXECUTE ''DELETE FROM '' || quote_ident(TG_ARGV[0]);


Jan

>
> NOTICE:  b wert
> NOTICE:  Error occurred while executing PL/pgSQL function checkint
> NOTICE:  line 4 at SQL statement
> ERROR:  parser: parse error at or near "$1"
>
> Does anybody know what I can do?
>
>     Hans
>
>
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--

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