java - how do i listview certain data only in my table -

i have 2 tables: subject , notes table. want listview notes have same subject name chosen.

first listview of subject(view_subj) when clicked goes listview of notes of subject, , add button inserts notes subject view_subj.java is:

public class view_subj extends listactivity {   private final string sample_db_name = "project"; private final string sample_table_name = "subject";  sqlitedatabase sampledb = null;  arraylist<string> results = new arraylist<string>(); /** called when activity first created. */  public void onlistitemclick(listview l, view view, final int position, long id) {     // todo auto-generated method stub     super.onlistitemclick(l, view, position, id);            intent in = new intent (view_subj.this,view_ppt_list.class);     string subj = (l.getitematposition(position)).tostring();     toast.maketext(getapplicationcontext(), subj, toast.length_short).show();     in.putextra("com.example.tinio_bolasa_project.sub1", subj);     startactivity(in); }  public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);         try {         sampledb =  this.openorcreatedatabase(sample_db_name, mode_private, null);         //name, mode mode_world_readable, mode_world_writeable, factory          /*sampledb.execsql("create table if not exists " +                 sample_table_name +                 " (lastname varchar, firstname varchar," +                 " city varchar, age int(3));");*/            cursor c = sampledb.rawquery("select * " +                 sample_table_name, null);            if (c != null ) {             if  (c.movetofirst()) {                 {                     string subid =  c.getstring(c.getcolumnindex("subj_id"));                     string subject =  c.getstring(c.getcolumnindex("subjname"));                      results.add(subid + subject);                 }while (c.movetonext());             }          }          this.setlistadapter(new arrayadapter<string>(this,   android.r.layout.simple_list_item_1,results));      } catch (sqliteexception se ) {         log.e(getclass().getsimplename(), "could not create or open database");     } {         if (sampledb != null)              //sampledb.execsql("delete " + sample_table_name);             sampledb.close();     } } } 

my view_ppt_list.java:

public class view_ppt_list extends listactivity { private final string sample_db_name = "project"; private final string ppt_table_name1 = "notes"; private final string ppt_table_name2 = "subject";  sqlitedatabase notesdb = null;   arraylist<string> results = new arraylist<string>();   public void onlistitemclick(listview l, view view, final int position, long id) {         // todo auto-generated method stub         super.onlistitemclick(l, view, position, id);                   intent ins = new intent (view_ppt_list.this,pptactivity.class);         string s = (l.getitematposition(position)).tostring();         ins.putextra("com.example.tinio_bolasa_project.finame", s);         // ins.putextra("entries", l.getitematposition(position).tostring());          toast.maketext(getapplicationcontext(),s ,toast.length_short ).show();         startactivity(ins);     }  public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);    string name = getsublabel();      try{          notesdb =  this.openorcreatedatabase(sample_db_name, mode_private, null);           notesdb.execsql("create table if not exists " +                 ppt_table_name1 +                  " ( notes_id integer primary key autoincrement, " +  "subjlabel varchar, " + "pptname varchar, " + "pptpath varchar);");      //     int x1 = getintent().getextras().getint("entries");          cursor c = notesdb.rawquery("select * notes subjlabel='"+name+"'",  null);       if (c != null ) {         if  (c.movetofirst()) {             {                  string ppt = c.getstring(c.getcolumnindex("pptname"));                  results.add(ppt);             }while (c.movetonext());         }      }      this.setlistadapter(new arrayadapter<string>(this,  android.r.layout.simple_list_item_1,results));  } catch (sqliteexception se ) {     log.e(getclass().getsimplename(), "could not create or open database"); } {     if (notesdb != null)          //sampledb.execsql("delete " + sample_table_name);         notesdb.close(); }        setcontentview(r.layout.activity_view__ppt__list);     button addppt = (button) this.findviewbyid(r.id.button1);     addppt.setonclicklistener(new onclicklistener() {          public void onclick(view arg0) {             // todo auto-generated method stub             intent inten = new intent (view_ppt_list.this,  add_ppt_activity.class);             startactivity(inten);         }      });     } public string getsublabel(){     string sublabel =  getintent().getstringextra("com.example.tinio_bolasa_project.finame");     return sublabel; } } 

and add_ppt_activity:

public class add_ppt_activity extends listactivity {  private final string sample_db_name = "project"; private final string ppt_table_name1 = "notes"; sqlitedatabase notesdb = null;  view_ppt_list getsubla = new view_ppt_list(); arraylist<string> filesinfolder = getfiles(environment.getexternalstoragedirectory()         .getpath()); public arraylist<string> getfiles(string directorypath) {     arraylist<string> myfiles = new arraylist<string>();     file f = new file(directorypath);     f.mkdirs();     file[] files = f.listfiles();     if (files.length == 0)         return null;     else {         for(int i=0; i<files.length;i++)             myfiles.add(files[i].getname());     }     return myfiles; }   public void onlistitemclick(listview l, view view, final int position, long id) {         // todo auto-generated method stub         super.onlistitemclick(l, view, position, id);     string filename = filesinfolder.get(position);         string filepath = environment.getexternalstoragedirectory()                 .getpath() + "/" + filename;          string subla = getsubla.getsublabel(); notesdb =  this.openorcreatedatabase(sample_db_name, mode_private, null); notesdb.execsql("insert " +                     ppt_table_name1 + " (subjid, "+ "pptname, " +  "pptpath)" +                      " values ('"+subla+"', '"+filename+"',  '"+filepath+"');");          intent in = new intent (add_ppt_activity.this,view_ppt_list.class);         startactivity(in);     } @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate); this.setlistadapter(new arrayadapter<string>(this, android.r.layout.simple_list_item_1,filesinfolder)); } } 

please help,