Re: Fwd: Re: question - plpgsql and query on table given by variable

On Mon, Aug 29, 2005 at 11:13:15AM +0200, Jaromír Kamler wrote:
>
> EXECUTE 'PERFORM AsText(the_geom) FROM ' || a || ';';

PERFORM is a PL/pgSQL command that isn't valid in an EXECUTE context.
Also, be careful when interpolating variables into an EXECUTE command;
see the comments about using quote_ident() and quote_literal() in
the "Executing Dynamic Commands" documentation. And the command
string doesn't need a terminating semicolon.

> IF FOUND THEN
> RETURN 'yes';
> END IF;
> IF FOUND THEN
> RETURN 'no';
> END IF;

Do you mean IF NOT FOUND? Also, using ELSIF (or ELSEIF) might be
more readable.

> SELECT n('b');
> ERROR: syntax error at or near "PERFORM" at character 1
> QUERY: PERFORM AsText(the_geom) FROM b;
> CONTEXT: PL/pgSQL function "n" line 7 at execute statement
> LINE 1: PERFORM AsText(the_geom) FROM b;
>
> When I use PPERFORM in normal way, it works. How I can reach some
> results from the query executed by EXECUTE?

The "Executing Dynamic Commands" documentation mentions a couple
of ways (FOR-IN-EXECUTE and OPEN-FOR-EXECUTE).

--
Michael Fuhr