Re: Expressing a result set as an array (and vice versa)?

CREATE OR REPLACE FUNCTION foreach( liste INTEGER[] ) RETURNS SETOF  
INTEGER AS $$
DECLARE  i INTEGER;
BEGIN  FOR i IN 1..icount(liste) LOOP    RETURN NEXT liste[i];  END LOOP;
END;
$$ LANGUAGE plpgsql;

CREATE AGGREGATE array_accum (    sfunc = array_append,    basetype = anyelement,    stype = anyarray,    initcond =
'{}'
);

SELECT array_accum( DISTINCT list_id ) FROM bookmarks;  array_accum
--------------- {1,2,3,4,5,7}

SELECT * FROM foreach( '{1,2,3,4,5,7}' ); foreach
---------       1       2       3       4       5       7



On Thu, 23 Mar 2006 20:44:32 +0100, Don Maier <dMaier@genome.stanford.edu>  
wrote:

> Good day,
>
> Is it possible to construct an array from an appropriate select  
> expression that generates a result set of unknown cardinality?
> To focus on the simple case:  Is it possible to construct a one- 
> dimensional array from a select of a single column in a table with an  
> unknown number of rows?
>
> Conversely, is it possible to construct a (single column) result set  
> from a select expression on a one-dimensional array with an unknown  
> number of elements?
>
> Thanks for any hints!
>
> Regards,
> Don Maier
>
>
>
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