Re: function returning result set of varying column

2008/6/3 maria s <psmg01@gmail.com>:
> Hi Ivan,
> If I have to know the column names then I can't use the Functions.
> As I said before, the columns will vary. or As Pavel Stehule said
> I will use arrays.
>
> Is anyone can show an example of returning a record with string and array?


postgres=# create or replace function foo(int) returns text[] as
$$select array(select 'kuku' || i from generate_series(1,$1) g(i))$$
language sql;
CREATE FUNCTION
Time: 69,730 ms
postgres=# select foo(10);                             foo

----------------------------------------------------------------{kuku1,kuku2,kuku3,kuku4,kuku5,kuku6,kuku7,kuku8,kuku9,kuku10}
(1 row)

Time: 1,739 ms
postgres=# select foo(5);              foo
---------------------------------{kuku1,kuku2,kuku3,kuku4,kuku5}
(1 row)

Time: 1,274 ms

>
> Thanks,
> Maria
>
> On Tue, Jun 3, 2008 at 9:57 AM, Ivan Sergio Borgonovo <mail@webthatworks.it>
> wrote:
>>
>> On Tue, 3 Jun 2008 09:41:27 -0400
>> "maria s" <psmg01@gmail.com> wrote:
>>
>> > Thanks for all your replies.
>> >
>> > Actually I don't know the number of columns that I am going to
>> > return.
>> >
>> > I have 2 tables. For a single entry E1  in one table(t1), I have
>> > to fetch all the matching entries for E1 from the other
>> > table(t2),  K1,..Kn. and finally the function should return E1,
>> > K1..Kn. So I don't know the number of columns that I am going to
>> > get.
>> >
>> > Is it possible to write a function that returns this kind of
>> > result?
>>
>> Up to my knowledge as Bart wrote in pl/pgsql you'll have to specify
>> somewhere the return type: in the function or in the select calling
>> the function.
>> If you use sql (not pl/pgsql) function you shouldn't be obliged to
>> specify the return type.
>> But I haven't written enough sql function to actually remember how
>> it works.
>>
>> If you post your tentative sql it could give us more clue.
>>
>> --
>> Ivan Sergio Borgonovo
>> http://www.webthatworks.it
>>
>>
>> --
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>
>