Dynamic query to fetch unique data.

I am using InventSite table to fetch unique SiteId and Name fields.

1. Query                                              query;
2. QueryBuildDataSource                   qbds;
3. QueryRun                                         qr;
4. InventSite                                         inventSite;
5.  
6. query      =  new Query();
7. qbds       =  query.addDatasource(tablenum(InventSite));
8. qbds.addGroupByField(fieldnum(InventSite, SiteId));
9. qbds.addGroupByField(fieldnum(InventSite, Name));
10.  
11. while(qr.next())
12. {
13.         inventSite   =  qr.get(tablenum(InventSite));
14.         info(strfmt("SiteId  : %1,  Name  : %2", inventSite.SiteId, inventSite.Name));
15. }

Note: If I comment Step-9, in the result we wont get Name details