android - SQLiteException : No such column -

sorry if question possibly duplicate.
i've looked other similar questions , answers, since i'm not familiar sql terms, i'm not able find solution trough these answers.

can please check code find what's wrong?

public class dbhelper extends sqliteopenhelper {      private static final string database_name = "todolist_db";     private static final string table_todos = "todos";     private static final string todo_title = "todo_title";     private static final string todo_category = "todo_category";     private static final string todo_year = "todo_year";     private static final string todo_month = "todo_month";     private static final string todo_day = "todo_day";     private static final string todo_hour = "todo_hour";     private static final string todo_minute = "todo_minute";     private static final string todo_priority = "todo_priority";       public dbhelper(context context) {         // context context , name database_name, no factory, version 1         super(context, database_name, null, 1);     }      public dbhelper(context context, string name, sqlitedatabase.cursorfactory factory, int version) {         super(context, name, factory, version);     }      //creating table first time     @override     public void oncreate(sqlitedatabase db) {         string sql = "create table " + table_todos +                 " (" + todo_title + " text, " +                 todo_category + " text, " +                 todo_year + " integer , " +                 todo_month + " text, " +                 todo_day + " integer, " +                 todo_hour + " text, " +                 todo_minute + " text, " +                 todo_priority + " integer);";          log.d("dbhelper", "sql : " + sql);         db.execsql(sql);     }      //upgrading table in  other versions of our program     @override     public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {         db.execsql("drop table if exist " + table_todos);         oncreate(db);     }      //add new todoobj database     public void inserttodo(todoobj todoobj) {         //hangi database olduðunu belirt         //dadatabase'i yazılabilir yap         sqlitedatabase db = this.getwritabledatabase();          //verileri tutması için container olustur.         contentvalues values = new contentvalues();          //verileri ekle         values.put("todo_title", todoobj.getmtitle());         values.put("todo_category", todoobj.getmcategory());         values.put("todo_year", todoobj.getmyear());         values.put("todo_month", todoobj.getmmonth());         values.put("todo_day", todoobj.getmday());         values.put("todo_hour", todoobj.getmhour());         values.put("todo_minute", todoobj.getmminute());         values.put("todo_priority", todoobj.getmprioritydrawableid());          //yeni satır olustur         db.insert(table_todos, null, values);         //commit         db.close();     }      public int deletetodo(string title) {         string = "title=?";         sqlitedatabase db = this.getwritabledatabase();         int numberofentriesdeleted = db.delete(database_name, where, new string[]{title});          return numberofentriesdeleted;     }      public arraylist<todoobj> getalltodos() {          // veritabanından gelen sonuçları saklayacağımız liste         arraylist<todoobj> todos = new arraylist<todoobj>();         sqlitedatabase db = this.getwritabledatabase();          //cursor methodu basit bir select oluþturmak için idealdir         //cursor objesi bize sonuçlar içinde dolaþma olanaðý saðlar         cursor cursor = db.query(table_todos,                 new string[]{"todo_title", "todo_category", "todo_year",                         "todo_month", "todo_day", "todo_hour", "todo_minute","todo_priority"}                 , null, null, null, null, null);          while (cursor.movetonext()) {             todoobj todoobj = new todoobj();             todoobj.setmtitle(cursor.getstring(0));             todoobj.setmcategory(cursor.getstring(1));             todoobj.setmyear(cursor.getint(2));             todoobj.setmmonth(cursor.getstring(3));             todoobj.setmday(cursor.getint(4));             todoobj.setmhour(cursor.getstring(5));             todoobj.setmminute(cursor.getstring(6));             todoobj.setmprioritydrawableid(cursor.getint(7));             todos.add(todoobj);         }          return todos;     }      public void deleteall() {         sqlitedatabase db = this.getwritabledatabase();         /*db.execsql("delete " + table_todos);         db.close();*/         db.delete(table_todos, null, null);         db.close();     }      public arraylist<todoobj> returnbycategory (string categoryname) {         // veritabanından gelen sonuçları saklayacağımız liste         arraylist<todoobj> todos = new arraylist<todoobj>();          sqlitedatabase db = this.getwritabledatabase();          //cursor methodu basit bir select oluþturmak için idealdir         //cursor objesi bize sonuçlar içinde dolaþma olanaðý saðlar         cursor cursor = db.query(table_todos,                 new string[]{"todo_title", "todo_category", "todo_year",                         "todo_month", "todo_day", "todo_hour", "todo_minute","todo_priority"}                 , null, null, null, null, null);          while (cursor.movetonext()) {             if(cursor.getstring(1).tostring().equalsignorecase(categoryname)){                  todoobj todoobj = new todoobj();                 todoobj.setmtitle(cursor.getstring(0));                 todoobj.setmcategory(cursor.getstring(1));                 todoobj.setmyear(cursor.getint(2));                 todoobj.setmmonth(cursor.getstring(3));                 todoobj.setmday(cursor.getint(4));                 todoobj.setmhour(cursor.getstring(5));                 todoobj.setmminute(cursor.getstring(6));                 todoobj.setmprioritydrawableid(cursor.getint(7));                 todos.add(todoobj);             }         }          return todos;     }  } 

wild guess: added (not specified) column after run app once.
unistalling , reinstalling app, solves problem.