Java – hibernate SQL query result mapping / conversion to object / class / bean

1 2: Select (table. * *) / (all columns) ok

String sql = "select t_student.* from t_student";
//String sql = "select t_student.id,t_student.name,... from t_student"; //select all column
sqlQuery query = session.createsqlQuery(sql);
query.addEntity(Student.class);//or query.addEntity("alias",Student.class);
//query.list();[Student@...,Student@...,Student@...]
query.setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP); //or other transformer
query.list(); //[{Student(or alias)=Student@...},{Student=Student@...}]

3: Selecting some columns (not all) is an error

String sql = "select t_student.id,t_student.name.t_student.sex from t_student";
sqlQuery query = session.createsqlQuery(sql);
query.addEntity(Student.class);
query.setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
query.list(); //Exception:invalid column/no column

I want "3" to work properly and map the results to student class. Like: student [id =? Name =? Sex =? (other fields are empty / default)] I don't know this error, please help me!

Solution

You can add further

For example:

public List<MessageExtDto> getMessagesForProfile2(Long userProfileId) {
    Query query = getSession().createsqlQuery("  "
            + " select a.*,b.* "
            + " from messageVO AS a "
            + " INNER JOIN ( SELECT max(id) AS id,count(*) AS count FROM messageVO GROUP BY messageConversation_id) as b ON a.id = b.id "
            + " where a.id > 0 "
            + " ")
            .addScalar("id",new LongType())
            .addScalar("message",new StringType())
            ......... your mappings
            .setResultTransformer(Transformers.aliasToBean(MessageExtDto.class));

    List<MessageExtDto> list = query.list();
    return list;
}