public class DbHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "QUIZ";
private static final String TABLE_QUIZ = "quiz";
private static final String KEY_ID = "id";
private static final String KEY_QUES = "question";
private static final String KEY_ANSWER = "answer";
private static final String KEY_OPTA = "opta";
private static final String KEY_OPTB = "optb";
private static final String KEY_OPTC = "optc";
private static final String KEY_OPTD = "optd";
private static final String q_level = "level";
private static final String QuestionNumber = "q_number";
private SQLiteDatabase dbase;
public String question, optionA, optionB, optionC, optionD, answer;

public DbHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    dbase = db;
    String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUIZ + " ( "
            + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUES
            + " TEXT, " + KEY_ANSWER + " TEXT, " + KEY_OPTA + " TEXT, "
            + KEY_OPTB + " TEXT, " + KEY_OPTC + " TEXT, " + KEY_OPTD  +" TEXT, " + q_level + " TEXT, " + QuestionNumber + " INTEGER)";
    db.execSQL(sql);
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','EASY','1')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q2','A1','A2','A3','A4','Answer','EASY','2')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q3','A1','A2','A3','A4','Answer','EASY','3')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q4','A1','A2','A3','A4','Answer','EASY','4')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q5','A1','A2','A3','A4','Answer','EASY','5')");



    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','MEDIUM','1')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','MEDIUM','2')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','MEDIUM','3')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','MEDIUM','4')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','MEDIUM','5')");


    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','HARD','1')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','HARD','2')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','HARD','3')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','HARD','4')");
    db.execSQL("INSERT INTO " + TABLE_QUIZ + "(" + KEY_QUES + ", " + KEY_OPTA + ", " + KEY_OPTB + ", " + KEY_OPTC + ", " + KEY_OPTD + ", " + KEY_ANSWER + ", " + q_level + ", " + QuestionNumber + ")VALUES(" +
            "'Q1','A1','A2','A3','A4','Answer','HARD','5')");
    addQuestions();
    //db.close();
}

private void addQuestions() {

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUIZ);
    onCreate(db);
}



public void getQuestByLevel(String level, int qnum) {
   String selectQuery = "SELECT * FROM " + TABLE_QUIZ +  " WHERE "+ q_level +"  = '"+ level +"' ORDER BY RANDOM() LIMIT 5;";


    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
        do {

            question=cursor.getString(cursor.getColumnIndex(KEY_QUES));
            optionA=cursor.getString(cursor.getColumnIndex(KEY_OPTA));
            optionB=cursor.getString(cursor.getColumnIndex(KEY_OPTB));
            optionC=cursor.getString(cursor.getColumnIndex(KEY_OPTC));
            optionD=cursor.getString(cursor.getColumnIndex(KEY_OPTD));
            answer=cursor.getString(cursor.getColumnIndex(KEY_ANSWER));


        } while (cursor.moveToNext());

    }
}

public class QuizActivity extends Activity {
int score = 0;
int qnum = 1;
TextView txtQuestion;
RadioButton rda, rdb, rdc, rdd;
Button butNext;
RadioGroup rdgrp;

String corAnswer = "";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    setContentView(R.layout.activity_quiz);
    DbHelper db = new DbHelper(this);
    rdgrp = (RadioGroup) findViewById(R.id.questionAndAnswers);
    txtQuestion = (TextView) findViewById(R.id.textView1);
    rda = (RadioButton) findViewById(R.id.radio0);
    rdb = (RadioButton) findViewById(R.id.radio1);
    rdc = (RadioButton) findViewById(R.id.radio2);
    rdd = (RadioButton) findViewById(R.id.radio3);
    butNext = (Button) findViewById(R.id.button1);


    corAnswer = "";
    onCreateQuestion();
}



@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_quiz, menu);
    return true;
}


public void onCreateQuestion() {
    String level = getIntent().getExtras().getString("level");
    DbHelper db = new DbHelper(this);
    db.getQuestByLevel(level, qnum);

    txtQuestion.setText(db.question);
    rda.setText(db.optionA);
    rdb.setText(db.optionB);
    rdc.setText(db.optionC);
    rdd.setText(db.optionD);
    corAnswer = db.answer;

    qnum++;

}

public void onClickNext(View view) {
    String level = getIntent().getExtras().getString("level");
    DbHelper db = new DbHelper(this);
    db.getQuestByLevel(level, qnum);

    RadioGroup grp = (RadioGroup) findViewById(R.id.questionAndAnswers);
    RadioButton answer = (RadioButton) findViewById(grp.getCheckedRadioButtonId());
    if (answer == null)
    {
        Toast.makeText(QuizActivity.this, "select an answer please", Toast.LENGTH_SHORT).show();


        return;
    }
    if (corAnswer!= null && corAnswer.equalsIgnoreCase((String) answer.getText()))
    {
        score++;
        Log.d("answer", "Your score" + score);
    }
    if (qnum <= 5) {


    } else {
        Intent intent = new Intent(QuizActivity.this, ResultActivity.class);
        Bundle b = new Bundle();
        b.putInt("score", score);
        intent.putExtras(b);
        startActivity(intent);
        finish();
    }

    txtQuestion.setText(db.question);
    rda.setText(db.optionA);
    rdb.setText(db.optionB);
    rdc.setText(db.optionC);
    rdd.setText(db.optionD);
    corAnswer = db.answer;
    qnum++;
    rdgrp.clearCheck();
}