mysql - Sphinx avg function from PHP-api -

i have mysql table:

create table person (id int(6) auto_increment primary key,name    varchar(30) not null,age int(4) not null); 

i run these inserts: insert person values(null, 'one', 42); insert person values(null, 'two', 49); insert person values(null, 'three', 16);

running:

select avg(age) person; 

gives me "35.6"

i index these table in sphinx. want run more or less same query in sphinx 1 run in mysql. command line issue command:

select avg(age) person_idx; 

fine. here "35.6".

now problem. need run query php. im using sphinxapi.php script comes sphinx-release. had @ docs , googled lot. cannot find way run these kind of functions (avg, sum etc) php. there way this?

in php have code:

require('sphinxapi.php'); $client = new sphinxclient(); $res = $client->query('', 'person_idx');    

where put "select avg(age)" part of sql-query? sphinxapi.php has methods can call. cannot see way decide select.

add before query() call

$client->setselect("avg(age) avg_age"); 

setselect equivalent 'select ...' part of sphinxql. in general need use as function use.