i want to apply joins ,on this code,


public List<SnStudentAssessment> getClassAssessment(
AssessmentCommand assessmentCommand, String username,
SnSchool snSchool) throws DataAccessException,
java.sql.SQLException, ParseException {

List<SnStudentAssessment> marksList = null;

Session session = this.getSession();
Transaction transaction = session.beginTransaction();
Query query = null;
StringBuffer queryBuffer = new StringBuffer(
"from com.tsb.nirvahak.student.hibernate.SnStudentAssessment");
if (assessmentCommand.getAssessmentType().equals("I")) {
HashMap searchFilters = new HashMap();
searchFilters.put("month", new SearchFilterData("month",
assessmentCommand.getMonth(),
SearchFilterData.TYPE_STRING_STR));
searchFilters.put("year", new SearchFilterData("year",
assessmentCommand.getYear(),
SearchFilterData.TYPE_NUMERIC_STR));
searchFilters.put("class_id", new SearchFilterData("class_id",
assessmentCommand.getKlassId(),
SearchFilterData.TYPE_NUMERIC_STR));
Iterator iterator = searchFilters.keySet().iterator();
boolean hasNext = iterator.hasNext();
if (hasNext) {
queryBuffer.append(" where ");
}
HibernateDaoUtil.appendGridFilter(queryBuffer, searchFilters);


query = session.createQuery(queryBuffer.toString());

} else if (assessmentCommand.getAssessmentType().equals("T")) {
queryBuffer.append("a.classId =:classId and a.term =:term");
query = session.createQuery(queryBuffer.toString());
query.setLong("classId", assessmentCommand.getKlassId());
query.setString("term", assessmentCommand.getTerm());
} else {
return new ArrayList<SnStudentAssessment>();
}

marksList = query.list();
Iterator<SnStudentAssessment> iter = query.iterate();

Iterator iterator = marksList.iterator();

while (iter.hasNext()) {
SnStudentAssessment assessment = (SnStudentAssessment) iter.next();
assessment.getGrade();
assessment.getMaths();
assessment.getSnStudent().getId();
assessment.getSnStudent().getFirstName();
assessment.getSnStudent().getLastName();

}

transaction.commit();
session.close();

return marksList;
}





please help me