Simple SQL

[Bob Messenger]

Is it possible to do something like:

select 1 as a, a*a;

in postgres?

[Terry Yapt]

Is it possible to do something like:

select 1 as a, a*a;

in postgres?

Perhaps on this way:

SELECT a, a*a FROM
(SELECT 1 AS a);

Greetings....

[Pavel Stehule]

Not

SELECT 1 as a, a*2;
ERROR: column "a" does not exist

Regards
Pavel
On Tue, 21 Oct 2003, Bob Messenger wrote:

Is it possible to do something like:

select 1 as a, a*a;

in postgres?
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TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match

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TIP 8: explain analyze is your friend

[Alvaro Herrera]

On Fri, Oct 24, 2003 at 07:25:44AM +0200, Pavel Stehule wrote:

Not

SELECT 1 as a, a*2;
ERROR: column "a" does not exist
But you can try

SELECT a, a*a FROM (select 1 as a);
On Tue, 21 Oct 2003, Bob Messenger wrote:

Is it possible to do something like:

select 1 as a, a*a;

in postgres?

--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Hay que recordar que la existencia en el cosmos, y particularmente la
elaboración de civilizaciones dentre de él no son, por desgracia,
nada idílicas" (Ijon Tichy)

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TIP 8: explain analyze is your friend

[Bob Messenger]

Alvaro Herrera wrote:

On Fri, Oct 24, 2003 at 07:25:44AM +0200, Pavel Stehule wrote:

Not

SELECT 1 as a, a*2;
ERROR: column "a" does not exist

But you can try

SELECT a, a*a FROM (select 1 as a);

On Tue, 21 Oct 2003, Bob Messenger wrote:

Is it possible to do something like:

select 1 as a, a*a;

in postgres?

alien=# SELECT a, a*a FROM (select 1 as a);
ERROR: sub-SELECT in FROM must have an alias
For example, FROM (SELECT ...) [AS] foo

Thanks for idea though. It led me to this:

alien=# SELECT a, a*a FROM (SELECT 2 AS a) AS a;
a | ?column?
---+----------
2 | 4
(1 row)