php merging arrays - php

Question

In the multidimensional array below, I would like to merge arrays that have the same merge_id. I'm not sure "merge" is the right word: in the example below, array['0'] should become array['0'] with in it array['0']['0'] and array['0']['1'], the latter being equal to array['1']. I hope this makes sense ...
The array comes out of the db sorted on merge_id so arrays with matching merge_id are always "next to" each other, and there will only ever be 2 with the same merge_id
As I loop through the array I know I need to keep a variable that is always equal to the previous merge_id and if there is a match between previous and current, then merge.
Array
(
[0] => Array
(
[client_id] => 5
[company_name] => company111_name
[id] => 3
[fee] => 111
[year] => 2009
[quarter] => 3
[date_inserted] => 1264948583
[description] => 2009 - Q3
[fee_type] =>
[merge_id] => a87ff679a2f3e71d9181a67b7542122c
[total_paid] => 0
[total_remainder] => 0
)
[1] => Array
(
[client_id] => 5
[company_name] => company111_name
[id] => 6
[fee] => 55.5
[year] => 2010
[quarter] => 2
[date_inserted] => 1264949470
[description] => 2010 - Q2
[fee_type] =>
[merge_id] => a87ff679a2f3e71d9181a67b7542122c
[total_paid] => 0
[total_remainder] => 0
)
[2] => Array
(
[client_id] => 5
[company_name] => company111_name
[id] => 4
[fee] => 111
[year] => 2009
[quarter] => 4
[date_inserted] => 1264948583
[description] => 2009 - Q4
[fee_type] =>
[merge_id] =>
[total_paid] => 0
[total_remainder] => 0
)
[3] => Array
(
[client_id] => 5
[company_name] => company111_name
[id] => 7
[fee] => 55.5
[year] => 2010
[quarter] => 3
[date_inserted] => 1264949470
[description] => 2010 - Q3
[fee_type] =>
[merge_id] =>
[total_paid] => 0
[total_remainder] => 0
)
)
Code
$merger = $data['search']['0']['merge_id'];
$i = 0;
foreach($data['search'] as $fee)
{
if($fee['merge_id'] == $merger)
{
//bump up & merge arrays
???
}
$merger = $fee['merge_id'];
$i++;
}

Answer 1

You can use the ID as key to put all items with the same ID in the same array:
$merged = array();
foreach ($data['search'] as $fee) {
if ($fee['merge_id'] == '') {
continue;
}
if (!isset($merged[$fee['merge_id']])) {
$merged[$fee['merge_id']] = array();
}
$merged[$fee['merge_id']][] = $fee;
}
$merged = array_values($merged);
Notice that this will skip the items with an empty merge ID. You could also use a default merge ID in that case by replacing continue; with $fee['merge_id'] = 0;.

Answer 2

foreach($array as $p)
$result[$p['merge_id']][] = $p;