how to get last id in database

1// Insert query 
2$query = "insert into users(username,fname,lname) values('sonarika','Sonarika','Bhadoria')"; 
3
4mysqli_query($con,$query); 
5
6// Get last insert id 
7$lastid = mysqli_insert_id($con); 

1  $db = db_connect();
2  $query = $db->query("SELECT * FROM users ORDER BY id DESC LIMIT 1");
3  $result = $query->getRow();