Aktualizacja zapytanie Nie działa żadne błędy znalezione PHP Mysql

<?php $dba = mysqli_connect('localhost', 'tendesig_zink', 'pswd', 'tendesig_zink_production') or die("Unable to connect to MySQL"); $query = " UPDATE tendesig_zink_dev.euid0_hikashop_product, tendesig_zink_production.euid0_hikashop_product SET tendesig_zink_dev.euid0_hikashop_product.product_quantity = tendesig_zink_production.euid0_hikashop_product.product_quantity WHERE tendesig_zink_dev.euid0_hikashop_product.product_id = tendesig_zink_production.euid0_hikashop_product.product_id"; if (mysqli_query($dba, $query)) { echo "Records inserted"; } else { echo "Error inserting records: " . mysqli_error($dba); } ?>
MLR.