Re: function with multiple return values

Scott Serr <serrs(at)theserrs(dot)net> wrote:

> I've created the following function:
>
> CREATE OR REPLACE FUNCTION latest ( lot_id int4,
> condition text, OUT perc smallint, OUT entry_date date )
> RETURNS SETOF record AS
> '
> BEGIN
> RETURN QUERY SELECT t1.perc, t1.entry_date
> FROM t1, t2
> WHERE t1.condition_id=t2.id and t1.lot_id = $1 and t2.code = $2
> ORDER BY entry_date DESC LIMIT 1;
> END;
> ' language 'plpgsql' VOLATILE;
>
> It works for this:
> select (latest(38787,'IP')).*
> returning perc and entry_date each in it's own column.
>
> Problem is:
> select (latest(38787,'IP')).*, (latest(38787,'FI')).*;
> returns 4 columns: perc, entry_date, perc, entry_date
>
> Tried:
> select perc as p1, perc as perc2 from (
> select (latest(38787,'IP')).*, (latest(38787,'FI')).*
> ) as foo;
> just to see -- it says perc is ambiguous... well yes it is! :)
>
> Ideas on how to uniquely name the first and second set of "perc,
> entry_date"?
> Or maybe there is a different way to return 2 values from a function?

You can use alias-names for the 2 queries, like:

test=*# select * from foo();
a | b
---+---
1 | 2
(1 row)

Time: 0.279 ms
test=*# select foobar.a as x, foobar.b as y, bar.* from (select * from foo()) foobar, (select * from foo()) bar ;
x | y | a | b
---+---+---+---
1 | 2 | 1 | 2
(1 row)

Now you have unique column names.

Andreas
--
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