NullPointerException when trying to insert into SQLite - Android

Question

Anyone who follows Android tags are probably familiar with me. I am having the hardest time implementing a SQLite database for my highscores. This is also my first time workin

Answer 1

On this line, you open the DB:

dh.openDB(db);

This stores the member variable of the database in DatabaseHelper.db (but nowhere else, and particularly not in Highscores.db). Then, you call:

dh.insert(x, y, db);

Using a null db object from Highscores. Lastly, within insert(), you use this null db object:

return db.insert(TABLE, null, values);

What you should do instead is use the following as your insert() method:

public long insert(long score, int percentage) { // Remove db parameter
    ContentValues values = new ContentValues();
    values.put(SCORE, score);
    values.put(PERCENTAGE, percentage);

    return db.insert(TABLE, null, values); // This will use the member variable
}

Then, call dh.insert(x, y); instead.

You should also change openDB(SQLiteDatabase db) to openDB() so that it is writing the correct DB; as it stands, it just overwrites the local variable's value (which changes nothing once the function's scope is done).