Load optimisation of a logic where query is running inside loop - php

Question

I have a rest api code block which is then being used for a report. The api returns collection of invoices, but adds few fields to individual invoices.
The fields are of order item level.
Currently this code works fetching the items information
private function pushAdditionalData($invoicedetails): array
{
foreach($invoicedetails as &$invoice) {
$connection = $this->resource->getConnection();
$sql = "SELECT SUM(TRUNCATE(soi.original_price * soi.qty_invoiced,2)) AS tot_original_price,SUM(TRUNCATE(cped.value * soi.qty_invoiced,2)) AS tot_cost,SUM(TRUNCATE(soi.price_incl_tax * soi.qty_invoiced,2)) AS tot_discount_price,sal.customer_id AS customer_id,sal.increment_id AS order_id FROM sales_order_item soi INNER JOIN catalog_product_entity_decimal cped ON soi.product_id = cped.entity_id INNER JOIN sales_order sal ON soi.order_id = sal.entity_id WHERE cped.attribute_id = 81 AND soi.order_id = ".$invoice['order_id'];
$data = $connection->fetchRow($sql);
$invoice['customer_id'] = $data['customer_id'];
$invoice['order_increment_id'] = $data['order_id'];
$invoice['product_cost'] = $data['tot_cost'];
$invoice['product_discounts'] = (string)abs($data['tot_original_price'] - $data['tot_discount_price']);
}
return $invoicedetails;
}
But as this is a query running inside a loop, I am trying to find a better way of doing this.
I tried using the same query with IN statement. But the data manipulation after that is getting too heavy and complex. This code is returning a similar result
private function testPushAdditionalData($invoicedetails)
{
foreach($invoicedetails as $invoice) {
$invoiceData[] = $invoice['order_id'];
}
$invoiceStr = implode(',', $invoiceData);
$connection = $this->resource->getConnection();
$sql = "SELECT sii.parent_id AS invoice_id,TRUNCATE(soi.original_price * soi.qty_invoiced,2) AS tot_original_price,TRUNCATE(cped.value * soi.qty_invoiced,2) AS tot_cost,TRUNCATE(soi.price_incl_tax * soi.qty_invoiced,2) AS tot_discount_price,sal.customer_id AS customer_id,sal.increment_id AS order_id FROM sales_order_item soi INNER JOIN catalog_product_entity_decimal cped ON soi.product_id = cped.entity_id INNER JOIN sales_order sal ON soi.order_id = sal.entity_id INNER JOIN sales_invoice_item sii ON soi.item_id = sii.order_item_id WHERE cped.attribute_id = 81 AND soi.order_id IN (".$invoiceStr.")";
$additionalInvoiceData = $connection->fetchAll($sql);
foreach($invoiceData as $invD) {
$totOrgPrice = $totCost = $totDisc = [];
foreach($additionalInvoiceData as $addInvD) {
if($invD == $addInvD['main_id']) {
$totOrgPrice[] = $addInvD['tot_original_price'];
$totCost[] = $addInvD['tot_cost'];
$totDisc[] = $addInvD['tot_discount_price'];
$customerId = $addInvD['customer_id'];
$orderId = $addInvD['order_id'];
}
}
$data[$invD] = [
'product_cost'=>number_format(array_sum($totCost),2),
'product_discounts'=>number_format(abs(array_sum($totOrgPrice) - array_sum($totDisc)),2),
'customer_id'=>$customerId,
'order_id'=>$orderId
];
}
foreach($invoicedetails as &$invoice) {
$invoice['customer_id'] = $data[$invoice['order_id']]['customer_id'];
$invoice['order_increment_id'] = $data[$invoice['order_id']]['order_id'];
$invoice['product_cost'] = (string)$data[$invoice['order_id']]['product_cost'];
$invoice['product_discounts'] = (string)$data[$invoice['order_id']]['product_discounts'];;
}
return $invoicedetails;
}
But the execution time of this is twice of the original one.
What is the best way I can optimise this code?