MySQL无法更新记录

Trying to update a record in MySQL via php form submission, but I keep recieving the error:

Error updating record: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SET phone='3609992399', address='123 Test Lane', city='Battle Gr' at line 4

if (isset($_POST['submit'])) {  
    $first_name = $_POST['first_name'];
    $last_name  = $_POST['last_name'];
    $email      = $_POST['email'];
    $phone      = $_POST['phone'];
    $address    = $_POST['address'];
    $city       = $_POST['city'];
    $state      = $_POST['state'];
    $zipcode    = $_POST['zipcode'];

    $mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);
    if ($mysqli->connect_errno) {
        echo "<p>MySQL error no {$mysqli->connect_errno} : {$mysqli->connect_error}</p>";
        exit();
    } else {
        $updateUser = "UPDATE users SET first_name='{$first_name}', last_name='{$last_name}', email='{$email}', phone='{$phone}', address='{$address}', city='{$city}', state='{$state}', zipcode='{$zipcode}' WHERE vendorid='{$user['vendorid']}'";
        if ($mysqli->query($updateUser) === TRUE) {
            echo "Record updated successfully";
        } else {
            echo "Error updating record: " . $mysqli->error;
        }
    }

    $mysqli->close();
}

Ive checked documentation on 5.5 and everything looks proper. Any clues?

You did not read the documentation very well.

Using SET multiple times is incorrect. Change it to:

UPDATE users SET
    first_name='{$first_name}',
    last_name='{$last_name}',
    email='{$email}',
    phone='{$phone}',
    address='{$address}',
    city='{$city}',
    state='{$state}',
    zipcode='{$zipcode}'
WHERE
    vendorid='{$user['vendorid']}'

From the documentation, second line:

UPDATE [LOW_PRIORITY] [IGNORE] table_reference
    SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
    [WHERE where_condition]
    [ORDER BY ...]
    [LIMIT row_count]

You should also educate yourself about security. Putting data directly from the browser in your SQL is not a good idea.