Re: Dynamic Assignment - Mailing list pgsql-general

From Pavel Stehule
Subject Re: Dynamic Assignment
Date
Msg-id AANLkTi=VbJb1RqFwi5Ww3QiEzJ+w-kpeEEFXsLw2vzTY@mail.gmail.com
Whole thread Raw
In response to Dynamic Assignment  ("Andy Chambers" <achambers@mcna.net>)
List pgsql-general
2011/3/23 Andy Chambers <achambers@mcna.net>:
> Hi All,
>
> In a trigger function, I'm trying to set the variable "pkey" to be one of
> the columns
> in the automatic variable "NEW".  Which one depends on some metadata that is
> available at
> run-time.  I'm having a hard time using an automatic variable in a dynamic
> execute command.
>
> I get the error "missing FROM-clause entry for table "new""
>
> Here's my function
>
> create or replace function refresh_row () returns trigger as $$
>
> declare
>  pkey bigint;
> begin
>  execute 'select NEW.esid' into pkey;
> end;
> $$ language plpgsql
>
> Obviously this particular code could be re-written as a simple assignment
> but I need the
> "esid" part to be dynamic.  Is this possible?

yes, it's possible

EXECUTE  'SELECT $1.' || quote_ident(attr_name) INTO pkey USING NEW;

Regards

Pavel Stehule

http://okbob.blogspot.com/2008/06/execute-using-feature-in-postgresql-84.html


>
> Cheers,
> Andy
>
> --
> Andy Chambers
>
> --
> Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-general
>

pgsql-general by date:

Previous
From: "Andy Chambers"
Date:
Subject: Dynamic Assignment
Next
From: Adrian Klaver
Date:
Subject: Re: pg_dump problems