Postgres and alias

["Fontana Daniel C \(Desartec S.R.L.\)" <desartecsrl@xxxxxxxxx>]

Perfect.

now let's imagine that '1234567890' is a function f_art_get_price(id_code),
which returns in a string like the following 'XXXZMMM1234567890123yyyy/mm/dd' 
where 1234567890123 is the price and yyyy/mm/dd the date it was last changed price.
How would you do in this case to obtain these values ​​separately?
without calling the function 2 times avoiding overloading the base?

something like this

select art.description,
	 f_art_get_price_str( art.id ) as ls_price_and_date
	SUBSTRING( ls_price_and_date, 7, 13 )
from articulos;

-----Mensaje original-----
De: Stelios Sfakianakis [mailto:sgsfak@xxxxxxxxx] 
Enviado el: jueves, 27 de agosto de 2020 12:59
Para: Fontana Daniel C (Desartec S.R.L.)
CC: pgsql-general@xxxxxxxxxxxxxxxxxxxx
Asunto: Re: Postgres and alias

Hmm, how about:

SELECT substr (ls_number, 3, 3)
FROM (VALUES('1234567890')) as t(ls_number);

St.

> On 27 Aug 2020, at 18:55, Fontana Daniel C (Desartec S.R.L.) <desartecsrl@xxxxxxxxx> wrote:
> 
> Hi, I am migrating a database from Sybase to PostgreSql 12.
> 
> This select in sybase works for me, but with postgresql it accuses me 
> "THERE IS NO COLUMN ls_numero"
> 
> select '1234567890' as ls_number,
>                  substr (ls_number, 3, 3);
> 
> Is it possible to get information from an alias in postgresql? how 
> would the code be?
> 
> 
> 
>