How to reference a subquery column alias?

Hi,

Just wrap your expression with another SELECT and operate with the aliases like

SELECT *, min_caudal + max_caudal AS diferencia FROM (
...your expression...
)

2010/8/9 José María Terry Jiménez <jtj@tssystems.net>:

Hello

Yesterday a list user solved me a problem with a sententence with two
subqueries. The solution was this:

SELECT remota_id,min(hora),max(hora), (SELECT caudal FROM historicos WHERE
remota_id=ooo.remota_id AND hora=min(ooo.hora)) as min_caudal, (SELECT
caudal FROM historicos WHERE remota_id=ooo.remota_id AND hora=max(ooo.hora))
as max_caudal from historicos AS ooo GROUP BY remota_id ORDER BY remota_id;

The issue now is i want to do some calculations with the subqueries columns
(min_caudal and max_caudal), for example adding them. (Get a new column with
max_caudal and min_caudal (alias) added)

I have tried to add in the SELECT;
,max_caudal+min_caudal as diferencia
,ooo.max_caudal+ooo.min_caudal as diferencia
,historicos.max_caudal+historicos.min_caudal as diferencia
,(SELECT max_caudal+min_caudal) as diferencia

I've read the SELECT and Table Expressions documentation pages, but didn't
found a solution.

Can anyone tell me how to reference or make the calculation with those alias
names?

TIA

Best,

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Sergey Konoplev

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Hello Sergey

Thanks by your answer, this worked after i add at the end an AS xxx
clause, because an error telling me something about subqueries in FROM
must have an alias, so i did it:

SELECT *, min_caudal + max_caudal AS diferencia FROM (
...your expression...
) AS temp

and worked

Best,

Sergey Konoplev escribió:

Hi,

Just wrap your expression with another SELECT and operate with the aliases like

SELECT *, min_caudal + max_caudal AS diferencia FROM (
...your expression...
)

2010/8/9 José María Terry Jiménez <jtj@tssystems.net>:

Hello

Yesterday a list user solved me a problem with a sententence with two
subqueries. The solution was this:

SELECT remota_id,min(hora),max(hora), (SELECT caudal FROM historicos WHERE
remota_id=ooo.remota_id AND hora=min(ooo.hora)) as min_caudal, (SELECT
caudal FROM historicos WHERE remota_id=ooo.remota_id AND hora=max(ooo.hora))
as max_caudal from historicos AS ooo GROUP BY remota_id ORDER BY remota_id;

The issue now is i want to do some calculations with the subqueries columns
(min_caudal and max_caudal), for example adding them. (Get a new column with
max_caudal and min_caudal (alias) added)

I have tried to add in the SELECT;
,max_caudal+min_caudal as diferencia
,ooo.max_caudal+ooo.min_caudal as diferencia
,historicos.max_caudal+historicos.min_caudal as diferencia
,(SELECT max_caudal+min_caudal) as diferencia

I've read the SELECT and Table Expressions documentation pages, but didn't
found a solution.

Can anyone tell me how to reference or make the calculation with those alias
names?

TIA

Best,

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Scanned with Copfilter Version 0.84beta3a (ProxSMTP 1.6)
AntiVirus: ClamAV 0.95.2/11523 - Mon Aug 9 19:20:40 2010
by Markus Madlener @ http://www.copfilter.org