Re: How to remove n-first elements from array?

From: Merlin Moncure <mmoncure(at)gmail(dot)com>
To: aasat <satriani(at)veranet(dot)pl>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: How to remove n-first elements from array?
Date: 2012-12-17 14:08:11
Message-ID: CAHyXU0wBJsuWVJ0RU0nq93kxYQ+C7mcBTo5Z9DqKHD6EAG757A@mail.gmail.com
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On Mon, Dec 17, 2012 at 3:27 AM, aasat <satriani(at)veranet(dot)pl> wrote:
> I found solution
>
> do $$
> declare
> v_array integer[] := array[1,2,3,4,5];
> v_array2 integer[];
> v_delete_elements integer :=2;
> v_new_index integer;
> begin
> v_new_index := array_lower(v_array, 1) + v_delete_elements;
>
> v_array2 := array_fill(v_array[v_new_index], ARRAY[1], ARRAY[v_new_index])
> || v_array[v_new_index+1:array_upper(v_array, 1)];
> raise notice '%', v_array2;
> end;
> $$
>
> NOTICE: [3:5]={3,4,5}

here's a solution that's a bit more general:
create or replace function remove_front(a anyarray, nkeep int) returns
anyarray as
$$
select a[array_upper(a, 1) - (nkeep - 1):array_upper(a, 1)];
$$ language sql immutable;

merlin

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