while inside while runs just once - php

Question

I have a problem with this code, the thing is that the inner while just runs once while the outer while does it right. What could be the problem?
Note: $producto_id is an array with ids.
$st_column = 0;
$nd_column = 1;
$posicionArray = 0;
if (($handle = fopen($ruta, "r")) != FALSE) {
fgetcsv($handle);
mysqli_query($link, "BEGIN");
while($producto_id[$posicionArray]){
$ins_producto = mysqli_query ($link, "INSERT INTO productos (encuesta_id, producto_id, nom_producto) VALUES ('".$encuesta_id."', '".$producto_id[$posicionArray]."', '".$nombre_producto[$posicionArray]."')");
while (($data = fgetcsv($handle, 0, "$delimiter")) != FALSE) {
if($producto_id[$posicionArray] == $data[$st_column]){
$ins_cupon = mysqli_query ($link, "INSERT INTO cupones (encuesta_id, producto_id, cupon, estado) VALUES ('".$encuesta_id."', '".$producto_id[$posicionArray]."', '".$data[$nd_column]."', 0)");
}
}
$posicionArray ++;
}
fclose($handle);
}

Answer 1

I believe you have a csv, which holds ids and coupons. It seems you are trying to go through your producto_id array and check if that exists in your CSV. This is what I would do:
CSV:
id,cupon
1,15165165
1,16516151
2,16841684
PHP:
function turn_csv_to_array($csv) {
$result = array();
if (($h = fopen($csv, "r")) != FALSE) {
$header = fgetcsv($h);
while ($row = fgetcsv($h)) {
$result[] = array_combine($header, $row);
}
fclose($h);
}
return $result;
}
$coupons = turn_csv_to_array("test.csv");
$product_ids = [1, 2, 3, 4];
foreach ($product_ids as $pid) {
// INSERT PRODUCT TO PRODUCT_DB
foreach ($coupons as $c) {
if ($pid == $c['id']) {
// INSERT PRODUCT TO COUPONS_DB
}
}
}

Answer 2

It all depends on what you meant by:
($data = fgetcsv($handle, 0, "$delimiter")
if you meant:
($data == fgetcsv($handle, 0, "$delimiter"))
that is the value of data is equal to the result of fgetcsv
then your code is wrong. and switch to "=="
if you mean:
($data = fgetcsv($handle, 0, "$delimiter"))
and fgetcsv can return a "0" then that is why.
using "assignments" in the middle of if statements is always bad practice.
if you do an assignment in the middle of your if statement, the value of the assignment is passed on to the boolean expression. Any value other than 0 is considered true. otherwise a 0 is considered false.