Mysql return value

Question

I have a small php page like below that I would like to return the "auto-incremented_id" from this insert.

Only requirement is that I can read the number from an android application. I'm sure I could look it up but is there a code SQL code I can check on success that will return it?

Here's the php:

<?php

//Make connection
$con = mysqli_connect('xxxxx', 'xxxxxxx', 'xxxxx');


//check connection
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

//change db to andriodnfp db
mysqli_select_db($con, 'andriodnfp');

$table = 'USER';

$fbid   = htmlspecialchars($_GET["fbid"]);
$social = htmlspecialchars($_GET["social"]);


$name = htmlspecialchars($_GET["name"]);
$name = !empty($name) ? "'$name'" : "NULL";

$fname = htmlspecialchars($_GET["fname"]);
$fname = !empty($fname) ? "'$fname'" : "NULL";

$username = htmlspecialchars($_GET["username"]);
$username = !empty($username) ? "'$username'" : "NULL";

$email = htmlspecialchars($_GET["email"]);
$email = !empty($email) ? "'$email'" : "NULL";

$picture = htmlspecialchars($_GET["picture"]);
$picture = !empty($picture) ? "'$picture'" : "NULL";

$other = htmlspecialchars($_GET["other"]);
$other = !empty($other) ? "'$other'" : "NULL";

if (!$fbid == '') {

    if (!mysqli_query($con, 'INSERT INTO ' . $table . ' ( facebookID, social_outlet, Name, first_name, username, email, picture, significant_other) VALUES ("' . $fbid . '","' . $social . '","' . $name . '","' . $fname . '","' . $username . '","' . $email . '","' . $picture . '","' . $other . '")')) {
        printf("Errormessage: %s\n", mysqli_error($con));
    };
}

mysqli_close($con);

//$posts = array($json);
$posts = array(
    1
);
header('Content-type: application/json');
echo json_encode(array(
    'posts' => $posts
));

?>

Answer 1

Try this: mysqli_insert_id

if (mysqli_query($con, 'INSERT INTO '.$table.' ( facebookID, social_outlet, Name, first_name, username, email, picture, significant_other) VALUES ("'.$fbid.'","'.$social.'","'.$name.'","'.$fname.'","'.$username.'","'.$email.'","'.$picture.'","'.$other.'")') === false) {
    printf("Errormessage: %s\n", mysqli_error($con));
    die();
}
$id = mysqli_insert_id($con);

You should also probably die after an error.

Also, you should compare the query with datatype as well ===, this ensures that it truly failed, not returned a value which evaluates to false. -- but it's not likely it returned something for an insert right?

Suppose you have a table in the database that looks like this:

id, username, user_level
1, dave, 0
2, jcaruso, 1

Suppose user_level was an integer, (0 = user, 1 = administrator). Doing a select such as SELECT user_level FROM table WHERE id=1 would return 0 and if you compare that with ==, it would be true. 0==false.