Unset an multidimensional array by key - php

Question

$series = array();
while($row = mysql_fetch_assoc($result)) {
$series[$row["data_id"]][] = $row;
}
The output from a print_r on $series yields for two example series:
Array (
[1] => Array ( [0] => Array ( [id] => 1 [data_id] => 1 [time_id] => 1
[data] => 1 ) [1] => Array ( [id] => 2 [data_id] => 1 [time_id] => 2
[data] => 3 ) )
[2] => Array ( [0] => Array ( [id] => 6 [data_id] => 2 [time_id] => 1
[data] => 7 ) [1] => Array ( [id] => 7 [data_id] => 2 [time_id] => 2
[data] => 4 ) )
My question: how do I unset the multidimensional array so it contains only [data] and none of the other keys? I still want $series to contain [1] and [2] but I do not want the respective sub-arrays to contain any other keys other than [data].
In fact, since I am reducing the subarrays to contain a single key, I would really like to get rid of the subarrays altogether so that I have two arrays:
$series[1] = array(1,3) and
$series[2] = array(7,4)

Answer 1

Try this :
$series = array();
while($row = mysql_fetch_assoc($result)) {
$series[$row["data_id"]][] = $row['data'];
}

Answer 2

I think you can loop in your array and build a new one keeping only data details
$array = array ('1' => array ( '0' => array ( 'id' => 1, 'data_id' => 1, 'time_id' => 1, 'data' => 1 ), '1' => array ( 'id' => 2, 'data_id' => 1, 'time_id' => 2, 'data' => 3 ), ),
'2' => array ( '0' => array ( 'id' => 6, 'data_id' => 2, 'time_id' => 1, 'data' => 7 ), '1' => array ( 'id' => 7, 'data_id' => 2, 'time_id' => 2, 'data' => 4 ) ));
$i= 0;
$n= 0;
$series = array();
foreach($array as $dato)
{
$series[$i] = array();
foreach($dato as $data)
{
foreach($data as $key => $value)
{
if($key == 'data')
{
$series[$i][$n] = $value;
$n++;
}
}
}
$n = 0;
$i++;
}
var_dump($series);
This will output
array (size=2)
0 =>
array (size=2)
0 => int 1
1 => int 3
1 =>
array (size=2)
0 => int 7
1 => int 4
Live demo