MySQL insert not showing anything - php

Question

How can I make the database entry code work? Right now nothing shows when I run this code.
public function hookActionValidateOrder()
{
$products=[];
$ids_product_attribute=[];
$references=[];
$stocks= [];
for($i=0;Context::getContext()->cart->getProducts()[$i]['id_product'];$i++)
{
array_push($products,Context::getContext()->cart->getProducts()[$i]['id_product']);
array_push($ids_product_attribute,Context::getContext()->cart->getProducts()[$i]['id_product_attribute']);
array_push($references,Context::getContext()->cart->getProducts()[$i]['reference']);
array_push($stocks,Context::getContext()->cart->getProducts()[$i]['stock_quantity']);
die(Db::getInstance()->execute("
INSERT INTO cart_log (products, ids_product_attribute, references, stocks, time)
VALUES ($products[$i], $ids_product_attribute[$i], $references[$i], $stocks[$i])"));
}
// var_dump($products);
// var_dump($ids_product_attribute);
// var_dump($references);
// var_dump($products);
}

Answer 1

I would write this function this way:
public function hookActionValidateOrder()
{
$defaults = [
'id_product' => null,
'id_product_attribute' => null,
'reference' => 0,
'stock_quantity' => 0
];
$stmt = Db::getInstance()->prepare("
INSERT INTO cart_log
SET products = :id_product,
ids_product_attribute = :id_product_attribute,
references = :reference,
stocks = :stock_quantity");
$products = Context::getContext()->cart->getProducts();
foreach ($products as $product) {
$values = array_merge($defaults, array_intersect_key($product, $defaults));
$stmt->execute($values);
}
}
This example shows usage of query parameters in a prepared statement, so you don't try to interpolate PHP variables directly into your SQL query. Query parameters make it easier to write error-free SQL code, and they protect you from accidental SQL injection errors (also malicious attacks).
I recommend calling your cart->getProducts() once, and save the result in a local variable. I'm not sure what that function does, but I suppose it's running another SQL query. You shouldn't run the same SQL query many times for each loop, that will increase load to your database server.
The business about array_merge(array_intersect_key()) is to make sure the values array has both all of the needed keys, and no other keys besides the needed keys. Then it can be passed as-is to PDOStatement::execute().
I'm using an alternative form for INSERT that is supported by MySQL, using SET column = value ... syntax. I find this makes it easier to make sure I've matched a column to each value and vice-versa.
As mentioned in the comments above, you must enable exceptions in the database connector. I'm assuming your getInstance() function returns a PDO connection, so you can pass the array of parameters to execute(). You need to enable PDO exceptions as described here: https://www.php.net/manual/en/pdo.error-handling.php
If you don't enable exceptions, you should check the return value of prepare() and execute() to see if either is === false, and if so then log the errorInfo() (read the PHP doc I linked to about error handling).

Answer 2

I detected two error in your query:
You insert 5 fields, but only 4 values.
In value you don't add '' char if values string
Example: if all fields with data type string
VALUES ('$products[$i]', '$ids_product_attribute[$i]', '$references[$i]', '$stocks[$i]', 'Field 5')