I just update the method : Replace it with
function _real_escape( $string ) {
if ( is_resource( $this->dbhs['global_r'] ) ) {
if ( $this->use_mysqli ) {
return mysqli_real_escape_string( $this->dbhs['global_r'] , $string );
} else {
return mysql_real_escape_string( $string, $this->dbhs['global_r'] );
}
} else {
return addslashes( $string );
}
}