Re: Could someone help me fix my array_list function? - Mailing list pgsql-sql

Would the same work for pg_user and pg_group?

It would be handy at times to easily check wether or not someone is member 
of a group...
and since in pg_group the usernumbers are stored, one might need to do a 
few lookups:
would it be hard to put such a thing in a view, or is that not-smart 
thinking here?

I have to admit, arrays are still a bit hazy to me, in how to use them 
properly in databases...
so I stick to the older solutions...

Michiel

At 15:27 20-1-2003 -0800, Joe Conway wrote:
>Guy Fraser wrote:
>>This is what I want to do:
>>select attribute,array_list(values,1,sizeof(values)) as value from av_list;
>>Turn :
>>  attr6 | {val3,val7,val4,val5}
>>Into :
>>  attr6 | val3
>>  attr6 | val7
>>  attr6 | val4
>>  attr6 | val5
>
>You didn't mention the version of PostgreSQL. If you're using < 7.3, good 
>luck ;-). If you are using 7.3, the following works:
>
>DROP TABLE mail_aliases;
>CREATE TABLE mail_aliases(
>   a_mailbox text,
>   a_destination text[]
>);
>
>INSERT INTO mail_aliases VALUES ('alias1', '{dest1}');
>INSERT INTO mail_aliases VALUES ('alias2', '{dest2,dest1}');
>INSERT INTO mail_aliases VALUES ('alias3', '{dest3,dest4}');
>INSERT INTO mail_aliases VALUES ('alias4', '{dest3,dest4,dest5}');
>INSERT INTO mail_aliases VALUES ('alias5', '{dest6,dest7}');
>INSERT INTO mail_aliases VALUES ('alias6', '{dest3,dest7,dest4,dest5}');
>
>CREATE TYPE mail_aliases_list_type AS (a_mailbox text, a_destination_el text);
>CREATE OR REPLACE FUNCTION mail_aliases_list() RETURNS SETOF 
>mail_aliases_list_type AS '
>DECLARE
>   rec record;
>   retrec record;
>   low int;
>   high int;
>BEGIN
>  FOR rec IN SELECT a_mailbox, a_destination FROM mail_aliases LOOP
>   SELECT INTO low
> 
>replace(split_part(array_dims(rec.a_destination),'':'',1),''['','''')::int;
>   SELECT INTO high
> 
>replace(split_part(array_dims(rec.a_destination),'':'',2),'']'','''')::int;
>
>   FOR i IN low..high LOOP
>    SELECT INTO retrec rec.a_mailbox, rec.a_destination[i];
>    RETURN NEXT retrec;
>   END LOOP;
>  END LOOP;
>  RETURN;
>END;
>' LANGUAGE 'plpgsql';
>
>regression=# SELECT a_mailbox, a_destination_el FROM mail_aliases_list();
>  a_mailbox | a_destination_el
>-----------+------------------
>  alias1    | dest1
>  alias2    | dest2
>  alias2    | dest1
>  alias3    | dest3
>  alias3    | dest4
>  alias4    | dest3
>  alias4    | dest4
>  alias4    | dest5
>  alias5    | dest6
>  alias5    | dest7
>  alias6    | dest3
>  alias6    | dest7
>  alias6    | dest4
>  alias6    | dest5
>(14 rows)
>
>
>HTH,
>
>Joe
>
>
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