Codice PHP:
class Database
{

    var 
$config;
    var 
$p_connect false;
    var 
$db;
    var 
$num_query 0;
    
    function 
Database($config$p_connect)
    {
        
$this->config $config;
        
$this->p_connect $p_connect;
        
$this->num_query 0;

        
$this->connect();
        
$this->select_db();
    }

    function 
connect()
    {
        if (
$this->p_connect == true)
            
$this->db mysql_pconnect($this->config['dbhost'], $this->config['dbuser'], $this->config['dbpass']);
        else
            
$this->db mysql_connect($this->config['dbhost'], $this->config['dbuser'], $this->config['dbpass']);
        
        if (!
$this->db)
            die(
'Unable to connect to MySQL server. MySQL reported: '.mysql_error());

    }

    function 
select_db()
    {
        if(!
mysql_select_db($this->config['dbname']))
            die(
'Unable to select database. MySQL reported: '.mysql_error());
    }

# ................. 
Errore: Unable to select database. MySQL reported: No database selected