Rookie wrote an operation MySQL database class, unusually heavy. Please correct or ask for similar code

Beginners write an operation MySQL database class, the error is heavy. Please correct or ask for similar code
Class TDBOPR
{
public var $cn = new mysqli (' localhost ', ' root ', ' sa ', ' test ');
Connecting to a database
function Connected ()
{
return $CN Mysqli_connect_errno = = 0;
}
Execute SQL statement
function Execute ($S)
{
$CN, query ($S);
return $CN errno = = 0;
}
Reading data
function ReadData ($S, & $ResultData)
{
$ResultData = Query ($S), $CN
return $CN errno = = 0;
}
Close connection
function Close ()
{
$CN-Close ();
}
Invoke instance
var $db = new Tdbopr ();
if ($db, Connected ())
{
echo "The database connection was successful. ";
}
Else
{
echo "Database connection failed. ";
}
?>

------Solution--------------------


Class TDBOPR
{
public var $cn = new mysqli (' localhost ', ' root ', ' sa ', test);
Connecting to a database
function Connected ()
{
return $CN connect_errno <> 0;
}
Execute SQL statement
function Execute ($S)
{
$CN, query ($S);
return $CN errno <> 0;
}
Reading data
Execute SQL statement
function ReadData ($S, & $ResultData)
{
Resultdata = $cn, query ($S);
Print_r ($ResultData);
Echo '
';
Echo $CN-errno;
return $CN errno <> 0;
}
Close connection
function Close ()
{
$CN-Close ();
}
}

?>

