Increment counter in a foreach loop depending on condition result - php

Question

I have an array being generated from a mysql query which looks like the following. They key is the order_id value.
orders array
Array
(
[2646] => Array
(
[order_id] => 2646
)
[2647] => Array
(
[order_id] => 2647
)
[2650] => Array
(
[order_id] => 2650
)
[2658] => Array
(
[order_id] => 2658
)
)
I am looking at adding items to each row of the array with items from another array which looks like.
order_items array
Array
(
[0] => Array
(
[order_id] => 2646
[prod_code] => 2811
[order_qty] => 1
)
[1] => Array
(
[order_id] => 2646
[prod_code] => 2812A
[order_qty] => 3
)
[2] => Array
(
[order_id] => 2647
[prod_code] => 2812A
[order_qty] => 2
)
[3] => Array
(
[order_id] => 2647
[prod_code] => 2810
[order_qty] => 2
)
[4] => Array
(
[order_id] => 2650
[prod_code] => 2906
[order_qty] => 1
)
[5] => Array
(
[order_id] => 2650
[prod_code] => 2908
[order_qty] => 6
)
[6] => Array
(
[order_id] => 2650
[prod_code] => 2909
[order_qty] => 3
)
[7] => Array
(
[order_id] => 2650
[prod_code] => 2913
[order_qty] => 1
)
[8] => Array
(
[order_id] => 2658
[prod_code] => 2880
[order_qty] => 3
)
[9] => Array
(
[order_id] => 2658
[prod_code] => 2881
[order_qty] => 3
)
[10] => Array
(
[order_id] => 2658
[prod_code] => 2882
[order_qty] => 1
)
)
What i am having trouble working out it how to loop over the order_items array and insert the prod_code and order_qty values into the order array where the order_id values match. Here is what i have so far.
// create orders array - key by order_id
while ($order = mysqli_fetch_assoc($order_rows)) {
$orders[$order['order_id']] = $order;
}
// create the order_items array
while ($item = mysqli_fetch_assoc($item_rows)) {
$order_items[] = $item;
}
// update orders array with ordered items
$item_index = 1;
foreach ($order_items as $key => $value) {
// get the order id
$item_order_id = $value['order_id'];
// update orders array with ordered items grouped by order_id
if ($item_order_id == $orders[$item_order_id]['order_id']) {
$orders[$item_order_id]['prod_code_'.$item_index] = $value['prod_code'];
$orders[$item_order_id]['order_qty_'.$item_index] = $value['order_qty'];
// same order id so increment the counter
$item_index++;
} else {
// new order id start at 1
$item_index = 1;
}
}
My problem is that the counter does not reset back to 1 when we are looking at a new item_order_id.
The output i am trying to achieve for my array is something like this.
desired orders array output
Array
(
[2646] => Array
(
[order_id] => 2646
[prod_code_1] => 2811
[order_qty_1] => 1
[prod_code_2] => 2812A
[order_qty_2] => 3
)
[2647] => Array
(
[order_id] => 2647
[prod_code_1] => 2812A
[order_qty_1] => 2
[prod_code_2] => 2810
[order_qty_2] => 2
)
[2650] => Array
(
[order_id] => 2650
[prod_code_1] => 2906
[order_qty_1] => 1
[prod_code_2] => 2908
[order_qty_2] => 6
[prod_code_3] => 2909
[order_qty_3] => 3
[prod_code_4] => 2913
[order_qty_4] => 1
)
[2658] => Array
(
[order_id] => 2658
[prod_code_1] => 2880
[order_qty_1] => 3
[prod_code_2] => 2881
[order_qty_2] => 3
[prod_code_3] => 2882
[order_qty_3] => 1
)
)
Any feedback or assistance greatly appreciated.

Answer 1

You can do two passes:
Aggregate order items by order id
Construct final output
First pass
// create the order_items array
while ($item = mysqli_fetch_assoc($item_rows)) {
$order_items[$item['order_id']][] = $item;
}
Second pass
foreach($order_items as $order_id => $order_items) {
$record = ['order_id' => $order_id];
// add order items
foreach($order_items as $index => $order_item) {
foreach ($order_item as $attribute_name => $attribute_value) {
$key = sprintf('%s_%d', $attribute_name, $index + 1);
$record[$key] = $attribute_value;
}
}
// generate csv row with record here
}