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From: TIM CHILD <[email protected]>
To: SQL Padawan <[email protected]>
To: [email protected] <[email protected]>
Subject: Re: Strange sequences - how to construct?
Date: Sat, 23 Oct 2021 06:09:25 -0700 (PDT)
Message-ID: <[email protected]> (raw)
In-Reply-To: <tiUZZ67DYCE5aY4wDAfIXjzlghyf4ndcG2m7wWRd0Rq3rtyhd38iJ9fN2iG088MxWOQtEBlEbsLXzqq-RUYer6rXXfS67pjdwthg8YRIgQU=@protonmail.com>
References: <tiUZZ67DYCE5aY4wDAfIXjzlghyf4ndcG2m7wWRd0Rq3rtyhd38iJ9fN2iG088MxWOQtEBlEbsLXzqq-RUYer6rXXfS67pjdwthg8YRIgQU=@protonmail.com>

Here is a way using multiple sequences:

drop sequence if exists controller_sequence;
drop sequence if exists odd_values;
drop sequence if exists even_values;
create sequence if not exists controller_sequence;
create sequence if not exists odd_values start with 1;
create sequence if not exists even_values start with 1;
create function next_my_sequence() returns integer as
$body$
declare
choose integer;
begin
choose = nextval('controller_sequence');
if choose % 2 equals then
return nextval('even_values');
else
return nextval('odd_values');
end if;
end;
$body$
language plpgsql;
-- example: get 5 sequences
select next_my_sequence(), next_my_sequence(), next_my_sequence(), next_my_sequence(), next_my_sequence();



>     On 10/22/2021 12:29 PM SQL Padawan <[email protected]> wrote:
> 
> 
> 
>     Good afternoon to everybody.
> 
>     I wish to construct some weird sequences.
> 
>     1
>     1
>     2
>     2
>     &c.
> 
>     and with  3 ones, 4 ones... &c.
> 
>     Now, I know how to do a simple
>     1
>     2
>     3
>     4
> 
>     using both GENERATE_SERIES and using a RECURSIVE CTE.
> 
>     What I would like is to be able to construct my specified sequences using *_both_* GENERATE_SERIES *_and_* RECURSIVE CTEs.
> 
>     Regards,
> 
>     SQL Padawan!
> 
> 
> 
> 
> 
>     Sent with ProtonMail https://protonmail.com/ Secure Email.
> 
> 

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