Re: Function returning SETOF - Mailing list pgsql-general

On Thu, Dec 01, 2005 at 12:32:02PM -0500, Terry Lee Tucker wrote:
> List,
>
> I have a simple function:

I have a simpler one :)

CREATE OR REPLACE FUNCTION split_to_rows(TEXT, TEXT) /* Descriptive name */
RETURNS SETOF TEXT
STRICT
LANGUAGE sql
AS $$
    SELECT (string_to_array($1, $2))[s.i]
    FROM generate_series(
        1,
        array_upper(string_to_array($1, $2), 1)
    ) AS s(i);
$$;

Cheers,
D
> CREATE OR REPLACE FUNCTION parse_string (TEXT, TEXT) RETURNS SETOF TEXT AS '
> DECLARE
>     str             ALIAS FOR $1;           -- the string to parse
>     delimiter       ALIAS FOR $2;           -- the delimiter
>     field           TEXT;                   -- return value from split_part
>     idx             INTEGER DEFAULT 1;      -- field counter
>     funcName        TEXT DEFAULT ''parse_string'';  -- function name
>     dbg             BOOLEAN DEFAULT True;   -- debug print flag
> BEGIN
>     IF dbg THEN
>         RAISE NOTICE ''% ()'', funcName;
>     END IF;
>     SELECT INTO field split_part (str, delimiter, idx);
>     WHILE field != '''' LOOP
>         RETURN NEXT field;
>         idx = idx + 1;
>         SELECT INTO field split_part (str, delimiter, idx);
>     END LOOP;
>     RETURN;
> END;
> ' LANGUAGE 'plpgsql';
>
> As you can see, I'm using split_part to parse the string in a loop. I want
> this thing to return the set of values that make up the fields in the string.
> When I call the function from psql here is the error I'm getting:
> rnd=# select parse_string ('1/2/3/4/5', '/');
> NOTICE:  parse_string ()
> ERROR:  set-valued function called in context that cannot accept a set
> CONTEXT:  PL/pgSQL function "parse_string" line 14 at return next
>
> Then I tried this approach and got the same error:
> rnd=# select ARRAY(SELECT parse_string ('1/2/3/4/5', '/'));
> NOTICE:  parse_string ()
> ERROR:  set-valued function called in context that cannot accept a set
> CONTEXT:  PL/pgSQL function "parse_string" line 14 at return next
>
> Version Information:
> rnd=# select version();
>                                                    version
> --------------------------------------------------------------------------------------------------------------
>  PostgreSQL 7.4.6 on i686-redhat-linux-gnu, compiled by GCC gcc (GCC) 3.2.3
> 20030502 (Red Hat Linux 3.2.3-49)
>
> I'm sure that I'm doing something stupid. Any input would be appreciated...
>
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--
David Fetter david@fetter.org http://fetter.org/
phone: +1 415 235 3778

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