General method for adding new result sets to the object. Give a SQL statement, a PEAR::DB_result object or an array as input parameter and the method calls the appropriate method for this input.
string $resultset - SQL statement, an DB_result object or an array
mixed $params - parameters for the following functions
XML_sql2xml::addResult(), XML_sql2xml::addSql(), XML_sql2xml::addArray(), XML_sql2xml::addXmlFile()