Hello
I am not in clear what your use case is, but you may have a look at that:
http://www.depesz.com/2013/02/25/variables-in-sql-what-how-when/
The bottom line is that in a psql interactive session you cannot really set a variable as the result of a select statement (or at least I did not fine a way). Instead, depending on what you actually want to achieve, you may use a workaround storing a statement or part of it in a variable.
Here an example:
db=> create table test (id int);
CREATE TABLE
db => insert into test select generate_series(1,10);
INSERT 0 10
db => \set testvar 'sum(id) from test'
db => select :testvar;
sum
-----
55
(1 row)
Bye
Charles
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Edson F. Lidorio
Sent: Freitag, 25. Dezember 2015 14:23
To: pgsql-general@postgresql.org
Subject: [GENERAL] Strange syntax with select
Hello,
I excuse my ignorance with SQL and my English.
I wonder if these procedures are correct or is it a bug?
I'm trying to put the result of a select within the v_saldo_ini variable, except I realized that the postgresql created a table with v_saldo_ini variable.
See the steps below:
CREATE TABLE contas
(
vlr_saldo_inicial numeric(14,2)) ;
select sum(vlr_saldo_inicial) as saldo_ini
into v_saldo_ini
from contas;
--postgresql created v_saldo_ini table
select * from v_saldo_ini;
saldo_ini
-----------
20000.00
(1 record)
--if I executat = ro select below, returns the table v_saldo_ini already exists
select sum(vlr_saldo_inicial) as saldo_ini
into v_saldo_ini
from contas;
ERROR: relation "v_saldo_ini" already exists
I'm using version below PostgreSQL.
PostgreSQL 9.4.5 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit
--
Edson
