java - SQL Database in Android doesnt work -

i'm trying create database 3 columns name, wins, losses. datatable should have 1 line - 1 player. tried not working, app crashes. have 2 activities , 1 regular class. in main activity checks if players name in database , if not asks him enter name. in second activity (gameactivity) supposes show me name , how time won , lost computer. there 2 buttons in there, add win , add loss, each 1 should raise number of wins or losses. sql database class extend sqliteopenhelper

mainactivity

sqlgametable db; button btn; @override protected void oncreate(bundle savedinstancestate)  {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);     btn = (button) findviewbyid(r.id.leaderboards);     db = new sqlgametable(this);     if(db.getname() == "")     {         final score score = new score("", 0, 0);         button send = (button) findviewbyid(r.id.btnsend);         final edittext et = (edittext) findviewbyid(r.id.edittext1);         send.setvisibility(android.view.view.visible);         et.setvisibility(android.view.view.visible);         send.setonclicklistener(new onclicklistener()         {                    @override             public void onclick(view v)             {                 string name = et.gettext().tostring();                 score.setname(name);             }         });         db.addplayer("daniel", score.getwins(), score.getloses());         send.setvisibility(android.view.view.invisible);         et.setvisibility(android.view.view.invisible);     }     final intent = new intent(this, gameactivity.class);     btn.setonclicklistener(new onclicklistener()      {                    @override         public void onclick(view v)          {             startactivity(i);         }     }); } 

gameactivity

button awin, alose; sqlgametable scoretable; textview tv1, tv3, tv4; score score; string name; int win=0, lose=0; @override protected void oncreate(bundle savedinstancestate)  {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_game);     scoretable = new sqlgametable(this);     awin = (button) findviewbyid(r.id.button1);     alose = (button) findviewbyid(r.id.button2);     tv1 = (textview) findviewbyid(r.id.textview1);     tv3 = (textview) findviewbyid(r.id.textview3);     tv4 = (textview) findviewbyid(r.id.textview4);     name = scoretable.getname();     win = scoretable.getwin();     lose = scoretable.getlose();     tv1.settext(name + "");     tv3.settext(win + "");     tv4.settext(lose + "");     alose.setonclicklistener(new onclicklistener()      {         @override         public void onclick(view v)          {             lose++;             scoretable.reset();             scoretable.addplayer(name, win, lose);             lose = scoretable.getlose();             tv4.settext("" + (lose));         }     });     awin.setonclicklistener(new onclicklistener()      {         @override         public void onclick(view v)          {             win++;             scoretable.reset();             scoretable.addplayer(name, win, lose);             win = scoretable.getwin();             tv3.settext("" + (win));         }     }); } 

sqlgametable extends sqliteopenhelper

public static string database_name = "highscores"; public static string table_name = "scores"; public static string key_id = "id"; public static string key_name = "name"; public static string key_win = "win"; public static string key_lose = "lose"; public sqlgametable(context c)  {     super(c, database_name, null, 1); } @override public void oncreate(sqlitedatabase db)  {     string sql = "create table if not exists scores (id integer primary key autoincrement, name string, win integer, lose integer)";     db.execsql(sql); }  @override public void onupgrade(sqlitedatabase db, int oldversion, int newversion)  {  }  public void addplayer(string name, int win, int lose)  {     contentvalues values = new contentvalues();     values.put(key_name, name);     values.put(key_win, win);     values.put(key_lose, lose);     sqlitedatabase db = getwritabledatabase();     db.insert(table_name, null, values);     db.close(); } public void reset()  {     sqlitedatabase db = getwritabledatabase();     db.delete(table_name, null, null);     db.close(); } public string getname()  {     string sql = "select * " + table_name;     sqlitedatabase db = getwritabledatabase();     cursor c = db.rawquery(sql, null);     int row = c.getcolumnindex(key_name);     db.close();     return c.getstring(row); } public int getwin()  {     string sql = "select * " + table_name;     sqlitedatabase db = getwritabledatabase();     cursor c = db.rawquery(sql, null);     int row = c.getcolumnindex(key_win);     db.close();     return integer.parseint(c.getstring(row)); } public int getlose()  {     string sql = "select * " + table_name;     sqlitedatabase db = getwritabledatabase();     cursor c = db.rawquery(sql, null);     int row = c.getcolumnindex(key_lose);     db.close();     return integer.parseint(c.getstring(row)); }