How to set charset in import CSV file to mysql database?

Question

I wrote a code that imports data from a CSV file into the database. However, I have a problem with setting charset on cp1250. When I use Polish characters in the database I see strange characters. I tried to use the SET NAMES function, but it does not work - any ideas?

<?php
$conn = mysqli_connect("localhost", "b", "c", "d");

if (isset($_POST["import"])) {

$fileName = $_FILES["file"]["tmp_name"];

if ($_FILES["file"]["size"] > 0) {

$file = fopen($fileName, "r");

while (($column = fgetcsv($file, 10000, ",")) !== FALSE) {


$sqlInsert = "INSERT INTO evdb_Historia_Aktualizacja(ID,Imie_I_Nazwisko,Suma_Brutto_Przejazdy,Suma_Netto_Przejazdy,Gotowka_Przejazdy_Uber,Brutto_UberEats,Netto_UberEats,VAT_UberEats,Netto_Gotowka,Bonusy_Dodatki,Napiwki_Brutto,Napiwek_18,Napiwek,Dodatki_UberEats,Ilosc_Dni,Prowizja_Evelstar,Kwota_Po_Prowizji_Evelstar,VAT_Przejazdy,Faktury_Brutto,Faktury_Netto,VAT_Faktury,VAT_Nalezny,Suma_Bez_Skladek,Rodzaj_Umowy,Kwota_Skladek,Potracenia_Reczne,Potracenia_Stale,Przelew_Przewoz,Przelew_UberEats,Data_Od,Data_Do,Login)
values ('" . $column[0] . "','" . $column[1] . "','" . $column[2] . "','" . $column[3] . "','" . $column[4] . "','" . $column[5] . "','" . $column[6] . "','" . $column[7] . "','" . $column[8] . "','" . $column[9] . "','" . $column[10] . "','" . $column[11] . "','" . $column[12] . "','" . $column[13] . "','" . $column[14] . "','" . $column[15] . "','" . $column[16] . "','" . $column[17] . "','" . $column[18] . "','" . $column[19] . "','" . $column[20] . "','" . $column[21] . "','" . $column[22] . "','" . $column[23] . "','" . $column[24] . "','" . $column[25] . "','" . $column[26] . "','" . $column[27] . "','" . $column[28] . "','" . $column[29] . "','" . $column[30] . "','" . $column[31] . "')";
$result = mysqli_query($conn, $sqlInsert);      
if (! empty($result)) {
$type = "success";
$message = "CSV Data Imported into the Database";
} else {
$type = "error";
$message = "Problem in Importing CSV Data";
            }
        }
    }
}
?>