<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* Vérification de la connexion */
if (mysqli_connect_errno()) {
    printf("Echec de la connexion : %s\n", mysqli_connect_error());
    exit();
}

$mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City");

$city = "'s Hertogenbosch";

/* cette requête échoue car nous n'avons pas échappé $city */
if (!$mysqli->query("INSERT into myCity (Name) VALUES ('$city')")) {
    printf("Erreur : %s\n", $mysqli->sqlstate);
}

$city = $mysqli->real_escape_string($city);

/* cette requête, par contre, réussira car nous avons échappé $city */
if ($mysqli->query("INSERT into myCity (Name) VALUES ('$city')")) {
    printf("%d ligne insérée.\n", $mysqli->affected_rows);
} 

$mysqli->close();
?>

<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* Vérification de la connexion */
if (mysqli_connect_errno()) {
    printf("Echec de la connexion : %s\n", mysqli_connect_error());
    exit();
}

mysqli_query($link, "CREATE TEMPORARY TABLE myCity LIKE City");

$city = "'s Hertogenbosch";

/* cette requête échoue car nous n'avons pas échappé $city */
if (!mysqli_query($link, "INSERT into myCity (Name) VALUES ('$city')")) {
    printf("Error: %s\n", mysqli_sqlstate($link));
}

$city = mysqli_real_escape_string($link, $city);

/* this query with escaped $city will work */
if (mysqli_query($link, "INSERT into myCity (Name) VALUES ('$city')")) {
    printf("%d ligne insérée.\n", mysqli_affected_rows($link));
} 

mysqli_close($link);
?>