Updating Multiple Fileds with logged in user and SHA1 Password
$query = "UPDATE user SET username='$_POST[username]',
nicename='$_POST[nicename]',
email='$_POST[email]',
password=(SHA1)'$_POST[password]',
position='$_POST[position]',
race='$_POST[race]',
type='$_POST[type]' WHERE username=$_SESSION[admin_login]";

$nicename = mysqli_real_escape_string($connect, $_POST['nicename']);

$hashed_pass = sha1($_POST['password']);

//Query goes here

WHERE username='".$_SESSION[admin_login]."'";

$dbh = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);

$password = sha1($_POST[password]);

$stmt = $dbh->prepare("UPDATE user SET username = :username, nicename = :nicename, email = :email, password = :password, position = :position, race = :race, type = :type WHERE  = :username");
$stmt->bindParam(':username', $_POST['username']);
$stmt->bindParam(':nicename', $_POST['nicename']);
$stmt->bindParam(':email', $_POST['email']);
$stmt->bindParam(':password', $password);
$stmt->bindParam(':position', $_POST['position']);
$stmt->bindParam(':race', $_POST['race']);
$stmt->bindParam(':type', $_POST['type']);
$stmt->bindParam(':username', $_SESSION['admin_login']);

$stmt->execute();

<?php
    $link     = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');

    $username = mysqli_real_escape_string($link, (string) $_POST['username']);
    $nicename = mysqli_real_escape_string($link, (string) $_POST['nicename']);
    $email    = mysqli_real_escape_string($link, (string) $_POST['email']);
    $email    = preg_replace( '/^[_a-zA-Z0-9-]+(.[_a-zA-Z0-9-]+)*@[a-zA-Z0-9-]+(.[a-zA-Z0-9-]+)*.(([0-9]{1,3})|([a-zA-Z]{2,3})|(aero|coop|info|museum|name))$/', $email );
    $password = sha1((string) $_POST['password']);
    $position = mysqli_real_escape_string($link, (string) $_POST['position']);
    $race     = mysqli_real_escape_string($link, (string) $_POST['race']);
    $type     = mysqli_real_escape_string($link, (string) $_POST['type']);
    $admin    = $_SESSION['admin_login'];

    $query = "UPDATE `user`
              SET `username`='$username',
                  `nicename`='$nicename',
                  `email`='$email',
                  `password`='$password',
                  `position`='$position',
                  `race`='$race',
                  `type`='$type'
              WHERE `username`='$admin'";

    mysqli_query($link, $query);
    mysqli_close($link);