How to merge array by value - php

Question

I can generate array from mysql, if there is a way for making it easy. I get rows and currently I am rendering like that, if there is a way to generate on fly
3, 0.4311 |
3, 0.1803 |
4, 0.1149 |
4, 0.0775 |
5, 0.4291 |
5, 0.5100|
Considering this array, how to merge it :
Array
(
[0] => Array
(
[channel_id] => 3
[value] => 0.4311
)
[1] => Array
(
[channel_id] => 3
[value] => 0.1803
)
[2] => Array
(
[channel_id] => 4
[value] => 0.1149
)
[3] => Array
(
[channel_id] => 4
[value] => 0.0775
)
...
)
so it will look like this this:
Array
(
[0] => Array
(
[channel_id] => 3
[value] => 0.4311
[value] => 0.1803
)
[1] => Array
(
[channel_id] => 4
[value] => 0.1149
[value] => 0.0775
)
)
Here is the code that I generate this array:
while($row = $result->fetch_assoc()) {
$array[] = array('channel_id'=>$row['channel_id'],'value'=>$row['value'] );
}

Answer 1

OK this seem impossible, but this is closed I could get:
$channels_byid = array();
foreach($array as $v){
#$channel = $channels_byid[$v['channel_id']];
if ($array){
if(!is_array($channel[0])){
unset($channels_byid[$v['channel_id']]);
$channels_byid[$v['channel_id']] = $channel;
}
$channels_byid[$v['channel_id']][] = $v;
} else {
$channels_byid[$v['channel_id']] = $v;
}
}
print_r($channels_byid);
Which outputs:
[3] => Array
(
[0] => Array
(
[channel_id] => 3
[value] => 0.7513
)
[1] => Array
(
[channel_id] => 3
[value] => 0.7234
)
)
[4] => Array
(
[0] => Array
(
[channel_id] => 4
[value] => 0.9798
)
[1] => Array
(
[channel_id] => 4
[value] => 0.7625
)
)

Answer 2

Not exactly what you were after, but it might be useful. The channel_id becomes the top-level key and value becomes the values of a new array.
$data[] = array('channel_id' => 3, 'value' => 0.4311);
$data[] = array('channel_id' => 3, 'value' => 0.1803);
$data[] = array('channel_id' => 4, 'value' => 0.1149);
$data[] = array('channel_id' => 4, 'value' => 0.0775);
foreach($data as $k => $v) {
$merge[$v['channel_id']][] = $v['value'];
}
And the result of $merge is:
array(2) {
[3]=> array(2) {
[0]=> float(0.4311)
[1]=> float(0.1803)
}
[4]=> array(2) {
[0]=> float(0.1149)
[1]=> float(0.0775)
}
}