private static final String Database_path = "/data/data/relativlayoutjava/databases/";
private static final String Database_name = "computer.db";//NAME of database stored in Assets folder
private static final String Table_name = "computer";//name of table
private static final String uid = "_id";//name of column1
private static final String Question = "Question";//name of column2
private static final String OptionA = "OptionA";//name of column3
private static final String OptionB = "OptionB";//name of column4
private static final String OptionC = "OptionC";//name of column5
private static final String OptionD = "OptionD";//name of column6
private static final String Answer = "Answer";//name of column7
private static final int version = 1;//version of database signifies if there is any upgradation or not
public SQLiteDatabase sqlite;//object of type SQLiteDatabase
private Context context;//Context object to get context from Question Activity

public computer(Context context) {//constructor
    super(context, Database_name, null, version);
    this.context = context;
}

public void createDatabase() {
    createDB();
}

private void createDB() {

    boolean dbexist = DBexists();//calling the function to check db exists or not
    if (!dbexist)//if database doesnot exist
    {

        this.getReadableDatabase();//Create an empty file
        copyDBfromResource();//copy the database file information of assets folder to newly create file
    }
}

private void copyDBfromResource() {

    InputStream is;
    OutputStream os;
    String filePath = Database_path + Database_name;
    try {
        is = context.getAssets().open(Database_name);//reading purpose
        os = new FileOutputStream(filePath);//writing purpose
        byte[] buffer = new byte[1024];
        int length;
        while ((length = is.read(buffer)) > 0) {
            os.write(buffer, 0, length);//writing to file
        }
        os.flush();//flush the outputstream
        is.close();//close the inputstream
        os.close();//close the outputstream

    } catch (IOException e) {
        throw new Error("Problem copying database file:");
    }
}

public void openDatabase() throws SQLException//called by onCreate method of Questions Activity
{

    String myPath = Database_path + Database_name;
    sqlite = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}

private boolean DBexists()//Check whether the db file exists or not
{
    SQLiteDatabase db = null;
    try {
        String databasePath = Database_path + Database_name;
        db = SQLiteDatabase.openDatabase(databasePath, null, SQLiteDatabase.OPEN_READWRITE);
        db.setLocale(Locale.getDefault());
        db.setVersion(1);
        db.setLockingEnabled(true);
    } catch (SQLException e) {
        Log.e("Sqlite", "Database not found");
    }
    if (db != null)
        db.close();///close the opened file
    return db != null ? true : false;

}

public String readQuestion(int i)//Used to read the data from the Des.db file where id is given and we choose id randomly
{
    String Ans = "";//string that contains the required field  note that Ans is just a local string not related to Answer or Option...
    Cursor c = sqlite.rawQuery("SELECT " + Question + " FROM " + Table_name + " WHERE " + uid + " = " + i + "", null);//cursor to that query
    if (c.moveToFirst())
        Ans = c.getString(0);
    else
        Ans = "";
    return Ans;
}

public String readOptionA(int i)//Used to read the data from the Des.db file where id is given and we choose id randomly
{
    String Ans = "";//string that contains the required field  note that Ans is just a local string not related to Answer or Option...
    Cursor c = sqlite.rawQuery("SELECT " + OptionA + " FROM " + Table_name + " WHERE " + uid + " = " + i + "", null);//cursor to that query
    if (c.moveToFirst())
        Ans = c.getString(0);
    else
        Ans = "";
    return Ans;
}

public String readOptionB(int i)//Used to read the data from the Des.db file where id is given and we choose id randomly
{
    String Ans = "";//string that contains the required field  note that Ans is just a local string not related to Answer or Option...
    Cursor c = sqlite.rawQuery("SELECT " + OptionB + " FROM " + Table_name + " WHERE " + uid + " = " + i + "", null);//cursor to that query
    if (c.moveToFirst())
        Ans = c.getString(0);
    else
        Ans = "";
    return Ans;
}

public String readOptionC(int i)//Used to read the data from the Des.db file where id is given and we choose id randomly
{
    String Ans = "";//string that contains the required field  note that Ans is just a local string not related to Answer or Option...
    Cursor c = sqlite.rawQuery("SELECT " + OptionC + " FROM " + Table_name + " WHERE " + uid + " = " + i + "", null);//cursor to that query
    if (c.moveToFirst())
        Ans = c.getString(0);
    else
        Ans = "";
    return Ans;
}

public String readOptionD(int i)//Used to read the data from the Des.db file where id is given and we choose id randomly
{
    String Ans = "";//string that contains the required field  note that Ans is just a local string not related to Answer or Option...
    Cursor c = sqlite.rawQuery("SELECT " + OptionD + " FROM " + Table_name + " WHERE " + uid + " = " + i + "", null);//cursor to that query
    if (c.moveToFirst())
        Ans = c.getString(0);
    else
        Ans = "";
    return Ans;
}

public String readAnswer(int i)//Used to read the data from the Des.db file where id is given and we choose id randomly
{

    String Ans = "";//string that contains the required field
    Cursor c = sqlite.rawQuery("SELECT " + Answer + " FROM " + Table_name + " WHERE " + uid + " = " + i + "", null);//cursor to that query
    if (c.moveToFirst())
        Ans = c.getString(0);
    else
        Ans = "";
    return Ans;
}