Funzioni per Database MySQL

<?php

function crea () {
   $conn = connetti ();
   echo "<!--";
   return $conn;
}

function connetti () {
   return mysqli_connect("localhost", "utente", "password", "test");
}

function db_exec ($conn, $query) {
   return mysqli_query ($conn, $query);
}

function db_row ($rubrica ,$riga) {
   return @mysqli_fetch_assoc ($rubrica);
}

function db_numrows ($res) {
   return mysqli_num_rows ($res);
}

 ?>