Compare values from 2 array PHP - php

Question

I need to compare 2 values from 2 array.
I figured it out but the problem is that i need to do a comparasion between qty based on a unique id.
array 1 is from a csv:
prod_id,qty
1,1
2,3
3,1
4,3
5,1
array 2 is from database:
id,prod_id,qty
1,1,5
2,2,3
3,4,1
4,4,1
5,5,1
so now i have to compare this 2 arrays and get the difference between quantity,
for example:
id 1 has in database 5 qty and in csv 1 so it result +4
id 3 has no value in database and in csv has 1 so it result -1
i have tried with:
foreach($array1 as $csv) {
$id[] = $csv['id'];
$data[$csv['id']] = $csv['qty'];
}
foreach($array2 as $db) {
$data[$db['id']] = $db['totalQty'];
}
but it give me the result from database and result from csv.
Is there another way to compare the quantity and get only the differences ?
any help is appreciated.

Answer 1

If i got this correctly...
<?php
$csv = array(
0 => array('prod_id'=>1,'qty'=>1),
1 => array('prod_id'=>2,'qty'=>3),
2 => array('prod_id'=>3,'qty'=>1),
3 => array('prod_id'=>4,'qty'=>3),
4 => array('prod_id'=>5,'qty'=>1)
);
$data = array(
0 => array('id'=>1,'prod_id'=>1,'qty'=>5),
1 => array('id'=>2,'prod_id'=>2,'qty'=>3),
2 => array('id'=>3,'prod_id'=>4,'qty'=>1),
3 => array('id'=>4,'prod_id'=>4,'qty'=>1),
4 => array('id'=>5,'prod_id'=>5,'qty'=>1),
5 => array('id'=>6,'prod_id'=>6,'qty'=>7)
);
$result = array();
foreach ($data as $a=>$b) {
$data_id = $b['id'];
$data_prod_id = $b['prod_id'];
$data_qty = $b['qty'];
$in_csv = false;
foreach ($csv as $k=>$v) {
$csv_prod_id = $v['prod_id'];
$csv_qty = $v['qty'];
if ($data_prod_id == $csv_prod_id && $data_id == $csv_prod_id) {
$result[$data_id] = $data_qty - $csv_qty;
}
if ($data_id != $data_prod_id) {
$result[$data_id] = 0 - $csv_qty;
break;
}
if ($data_prod_id == $csv_prod_id) {
$in_csv = true;
}
if (!$in_csv) {
$result[$data_id] = $data_qty;
}
}
}
foreach ($result as $k=>$v) {
if ($v != 0) {
echo "ID $k has changed : $v <br>";
}
}