Part 3 – SQLiteOpenHelper

package com.codinginflow.myawesomequiz;

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import com.codinginflow.myawesomequiz.QuizContract.*;


public class QuizDbHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "MyAwesomeQuiz.db";
    private static final int DATABASE_VERSION = 1;

    private SQLiteDatabase db;

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        this.db = db;

        final String SQL_CREATE_QUESTIONS_TABLE = "CREATE TABLE " +
                QuestionsTable.TABLE_NAME + " ( " +
                QuestionsTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                QuestionsTable.COLUMN_QUESTION + " TEXT, " +
                QuestionsTable.COLUMN_OPTION1 + " TEXT, " +
                QuestionsTable.COLUMN_OPTION2 + " TEXT, " +
                QuestionsTable.COLUMN_OPTION3 + " TEXT, " +
                QuestionsTable.COLUMN_ANSWER_NR + " INTEGER" +
                ")";

        db.execSQL(SQL_CREATE_QUESTIONS_TABLE);
        fillQuestionsTable();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + QuestionsTable.TABLE_NAME);
        onCreate(db);
    }

    private void fillQuestionsTable() {
        Question q1 = new Question("A is correct", "A", "B", "C", 1);
        addQuestion(q1);
        Question q2 = new Question("B is correct", "A", "B", "C", 2);
        addQuestion(q2);
        Question q3 = new Question("C is correct", "A", "B", "C", 3);
        addQuestion(q3);
        Question q4 = new Question("A is correct again", "A", "B", "C", 1);
        addQuestion(q4);
        Question q5 = new Question("B is correct again", "A", "B", "C", 2);
        addQuestion(q5);
    }

    private void addQuestion(Question question) {
        ContentValues cv = new ContentValues();
        cv.put(QuestionsTable.COLUMN_QUESTION, question.getQuestion());
        cv.put(QuestionsTable.COLUMN_OPTION1, question.getOption1());
        cv.put(QuestionsTable.COLUMN_OPTION2, question.getOption2());
        cv.put(QuestionsTable.COLUMN_OPTION3, question.getOption3());
        cv.put(QuestionsTable.COLUMN_ANSWER_NR, question.getAnswerNr());
        db.insert(QuestionsTable.TABLE_NAME, null, cv);
    }
}

package com.codinginflow.myawesomequiz;

public class Question {
    private String question;
    private String option1;
    private String option2;
    private String option3;
    private int answerNr;

    public Question() {
    }

    public Question(String question, String option1, String option2, String option3, int answerNr) {
        this.question = question;
        this.option1 = option1;
        this.option2 = option2;
        this.option3 = option3;
        this.answerNr = answerNr;
    }

    public String getQuestion() {
        return question;
    }

    public void setQuestion(String question) {
        this.question = question;
    }

    public String getOption1() {
        return option1;
    }

    public void setOption1(String option1) {
        this.option1 = option1;
    }

    public String getOption2() {
        return option2;
    }

    public void setOption2(String option2) {
        this.option2 = option2;
    }

    public String getOption3() {
        return option3;
    }

    public void setOption3(String option3) {
        this.option3 = option3;
    }

    public int getAnswerNr() {
        return answerNr;
    }

    public void setAnswerNr(int answerNr) {
        this.answerNr = answerNr;
    }
}

package com.codinginflow.myawesomequiz;

import android.provider.BaseColumns;

public final class QuizContract {

    private QuizContract() {
    }

    public static class QuestionsTable implements BaseColumns {
        public static final String TABLE_NAME = "quiz_questions";
        public static final String COLUMN_QUESTION = "question";
        public static final String COLUMN_OPTION1 = "option1";
        public static final String COLUMN_OPTION2 = "option2";
        public static final String COLUMN_OPTION3 = "option3";
        public static final String COLUMN_ANSWER_NR = "answer_nr";
    }
}

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#795548</color>
    <color name="colorPrimaryDark">#5D4037</color>
    <color name="colorAccent">#FFEB3B</color>

    <color name="colorBackground">#BCAAA4</color>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorBackground"
    android:padding="16dp"
    tools:context="com.codinginflow.myawesomequiz.StartingScreenActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="30dp"
        android:text="My Awesome Quiz"
        android:textColor="@android:color/black"
        android:textSize="35sp" />

    <TextView
        android:id="@+id/text_view_highscore"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@id/button_start_quiz"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="32dp"
        android:text="Highscore: 0"
        android:textSize="20sp" />

    <Button
        android:id="@+id/button_start_quiz"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Start Quiz" />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorBackground"
    android:padding="16dp"
    tools:context="com.codinginflow.myawesomequiz.QuizActivity">

    <TextView
        android:id="@+id/text_view_score"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Score: 0"
        android:textColor="@android:color/black" />

    <TextView
        android:id="@+id/text_view_question_count"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/text_view_score"
        android:text="Question: 1/x"
        android:textColor="@android:color/black" />

    <TextView
        android:id="@+id/text_view_countdown"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:text="00:30"
        android:textColor="@android:color/black"
        android:textSize="40sp" />

    <TextView
        android:id="@+id/text_view_question"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/radio_group"
        android:layout_marginBottom="16dp"
        android:text="Here will be the question text\nHere will be the question text\nHere will be the question text"
        android:textAlignment="center"
        android:textColor="@android:color/black"
        android:textSize="20sp" />

    <RadioGroup
        android:id="@+id/radio_group"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true">

        <RadioButton
            android:id="@+id/radio_button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Option 1" />

        <RadioButton
            android:id="@+id/radio_button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Option 2" />

        <RadioButton
            android:id="@+id/radio_button3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Option 3" />

    </RadioGroup>

    <Button
        android:id="@+id/button_confirm_next"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/radio_group"
        android:layout_marginTop="16dp"
        android:text="Confirm" />

</RelativeLayout>

package com.codinginflow.myawesomequiz;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class StartingScreenActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_starting_screen);

        Button buttonStartQuiz = findViewById(R.id.button_start_quiz);
        buttonStartQuiz.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startQuiz();
            }
        });
    }

    private void startQuiz() {
        Intent intent = new Intent(StartingScreenActivity.this, QuizActivity.class);
        startActivity(intent);
    }
}