On 17-06-2014 22:44, François Beausoleil wrote:
Le 2014-06-17 à 14:22, Condor <condor@xxxxxxxxxx> a écrit :
I do select array_agg(ids) from x;
in ids I have int and result is :
array_agg
-------------
{3843,2,3543,33}
I want to access one element or first one direct in sql query like:
select array_agg(ids)[1] from x;
and to receive int value 2
Any hints how I can do it ?
This works for me in 9.1:
psql (9.1.13)
Type "help" for help.
svanalytics=> select (array_agg(x))[1] from
(values(3843),(2),(3543),(33)) t1(x) ;
array_agg
-----------
3843
Note the use of the extra parens around the array_agg call. This is
probably a parser issue more than anything else.
And also for performance did that is good I to do it in SQL or I
should do it in language that I use ? The result in query will return
about 2, 3 million rows.
Do you mean you will have an array of 2, 3 million elements, or 2, 3
million rows with a couple dozen elements each? I’m not sure which
will be easier / faster. I routinely work with million element result
sets (rows) and have no issues.
Hope that helps!
François
Ah, double brackets and works, I did not expect and try
select (array_agg(ids))[1] from x;
to work but its work.
I try:
select array_agg(ids)[1] from x;
Thank you
