Сравните два асинхронных значения при использовании Angularfire2

Использовать mysqli, поскольку mysql лишает

<?php
$mysqli = new mysqli("localhost", "yourUsername", "yourPassword", "yourDB");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
// Conside employee table with id,name,designation
$query = "INSERT INTO myCity VALUES (NULL, 'Ram', 'Developer')";
$mysqli->query($query);

printf ("New Record has id %d.\n", $mysqli->insert_id);

/* close connection */
$mysqli->close();
?>