$this->conn = mysql_connect ( $this->host, $this->user, $this->pass ) or die ( 'ERR_DB_CONNECT' );

$result = mysql_query ( $query, $this->conn ) or die ( mysql_error () );

$this->conn = mysqli_connect ( $this->host, $this->user, $this->pass ) or die ( 'ERR_DB_CONNECT' );

$result = mysqli_query ( $query, $this->conn ) or die ( mysqli_error () );