android - Database objects not getting executed -

i running following thread in service. but, if have 3 or 4 rows of data in database, last 1 not executed. if having 4 rows of data, 3 gets executed. can tell me reason this?

 new thread(new runnable() {         @override         public void run() {              list<greetings>greetings = db.getallgreetings();                  if(db.getgreetingscount()>0) {                      {                          (greetings g : greetings) {                              calendar cal = calendar.getinstance();                              d1 = cal.get(calendar.day_of_month);                              d2 = cal.get(calendar.month);                              d3 = cal.get(calendar.year);                              t1 = cal.get(calendar.hour);                              t2 = cal.get(calendar.minute);                              t3 = cal.get(calendar.am_pm);                              if (t3 == 1) {                                  t4 = "pm";                              } else {                                  t4 = "am";                              }                              stringbuilder strt = new stringbuilder().append(t1).append(" : ").append(t2)                                      .append(" ").append(t4);                               tc = strt.tostring();                              stringbuilder builder = new stringbuilder().append(string.valueof(d3) + "-").append((string.valueof(d2 + 1)) + "-")                                      .append(string.valueof(d1));                               d = builder.tostring();                              cdt = d + "\t" + tc;                              //log.d(cdt, "about execute mytask");                              time = g.gettime();                              date = g.getdate();                              phone = g.getphonenumber();                              msg = g.getmessage();                              id = g.getid();                              dnt = date + "\t" + time;                              //log.d(dnt, "about execute mytask");                              if (dnt.equals(cdt)) {                                  intent aint = new intent(getapplicationcontext(), alarmreceiver.class);                                   aint.putextra("msg", msg);                                  aint.putextra("phone", phone);                                  aint.putextra("id", id);                                  pendingintent pendingintent = pendingintent.getbroadcast(getapplicationcontext(), id, aint, pendingintent.flag_update_current);                                  alarmmanager.set(alarmmanager.rtc_wakeup, cal.gettimeinmillis(), pendingintent);                                  db.deletegreetings(g);                              }                           }                          k = db.getgreetingscount();                       } while ( k !=0 );                  }          }     }).start();      return start_not_sticky; 

the getallgreetings andgetgreetingscount class shown below

 public list<greetings> getallgreetings() {     list<greetings> greetinglist = new arraylist<greetings>();     // select query     string selectquery = "select  * " + table_greetings;      sqlitedatabase db = this.getwritabledatabase();     cursor cursor = db.rawquery(selectquery, null);      // looping through rows , adding list     if (cursor.movetofirst()) {         {             greetings greeting = new greetings();             greeting.setid(integer.parseint(cursor.getstring(0)));             greeting.setdate(cursor.getstring(1));             greeting.setphonenumber(cursor.getstring(2));             greeting.settime(cursor.getstring(3));             greeting.setmessage(cursor.getstring(4));             // adding contact list             greetinglist.add(greeting);         } while (cursor.movetonext());     }     cursor.close();     db.close();      // return greeting list     return greetinglist; }  public int getgreetingscount() {     string countquery = "select  * " + table_greetings;     sqlitedatabase db = this.getreadabledatabase();     cursor cursor = db.rawquery(countquery, null);     int = cursor.getcount();     cursor.close();     db.close();     // return count     return a; }