PL/SQL Oracle php AVG

Question

hi everyone :) im tryin to make AVG form salary(wynagrodzenie) but im doing something wrong , can someone correct me ???
it looks like this im trying to view avg salary(wynagrodzenie) from every departments(id_dzialu) , id_dzialu and wynagrodzenie are both in table pracownik(worker)
<?php
$c = oci_connect("xxx", "xxx", "localhost/XE");
$s = oci_parse($c, 'select id_dzialu
from pracownik;
where wynagrodzenie = :wynag');
$ba = array(':wynag' => 'avg');
foreach ($ba as $key => $val) {
oci_bind_by_name($s, $key, $ba[$key]);
oci_execute($s);
while (($row = oci_fetch_array($s, OCI_ASSOC))) {
foreach ($row as $item) {
echo $item." ";
echo "<br>\n";
?>

Answer 1

yes i gues so :D its my magic script
i was also trying to do something like this
$c = oci_connect("xxx", "xxx", "localhost/XE");
$s = oci_parse($c, 'select id_dzialu , avg(wynagrodzenie)
from pracownik
group by id_dzialu;
where ............'); what should i place in where ??? maybe avg(wynagrodzenie)???
$ba = array(.................); and what in here i want to view the array of avg salary of each department :)
/// id_dzialu is workers department id and avg(wynagrodzenie) is avg salary , just dont know how to construct this :P
or maybe you know some easier way to dispaly avg salary from my php oracle base ???