ANDROID STUDIO: Gradle does not build sql database

I am kind of new to android developing, but I usually seem to be able to find solutions to most bugs. However this time I was not able to find any info on my bug on the Internet. I am not certain what my bug really is but in short: I have a program where I use SQL to store the users credit. It used to work fine until one faithful day it just stopped running. Here is where the problem first occurs.

package com.inc.nicky.tapit;


MyDBHandler dbHandler = new MyDBHandler(this, null, null, 1);

    Product product =
            dbHandler.findProduct("Coins");
    eee=(TextView)findViewById(R.id.someID);
    if (product != null) {

        eee.setText(product.getQuantity());


    } else {
    product =
            new Product("Coins", 0);

    dbHandler.addProduct(product);
    eee.setText("0");
}

}

LogCat says that it cannot change the Text to product.getQuantity(). However if I remove this line and get to a future usage of the SQL the problem still remains (I cannot call product.getQuantity() even when I am not changing texts).

Here is more detailed report of the error:

Unable to start activity ComponentInfo{com.inc.nicky.tapit/com.inc.nicky.tapit.MainActivity}: android.content.res.Resources$NotFoundException: String resource ID #0x0
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2394)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2452)
        at android.app.ActivityThread.access$900(ActivityThread.java:172)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1302)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5586)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x0
        at android.content.res.Resources.getText(Resources.java:1408)
        at android.widget.TextView.setText(TextView.java:4949)
        at com.inc.nicky.tapit.MainActivity.lookUpProduct(MainActivity.java:42)
        at com.inc.nicky.tapit.MainActivity.onCreate(MainActivity.java:78)
        at android.app.Activity.performCreate(Activity.java:5451)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2358)

           

Here is MyDBHandler:

public class MyDBHandler extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 2;
private static final String DATABASE_NAME = "gameDB.db";
private static final String TABLE_PRODUCTS = "products";

public static final String COLUMN_ID = "_id";
public static final String COLUMN_PRODUCTNAME = "productname";
public static final String COLUMN_QUANTITY = "quantity";

public MyDBHandler(Context context, String name,
                   SQLiteDatabase.CursorFactory factory, int version) {
    super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}



@Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_PRODUCTS_TABLE = "CREATE TABLE " +
            TABLE_PRODUCTS + "("
            + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_PRODUCTNAME
            + " TEXT," + COLUMN_QUANTITY + " INTEGER" + ")";
    db.execSQL(CREATE_PRODUCTS_TABLE);
}

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

public void addProduct(Product product) {

    ContentValues values = new ContentValues();
    values.put(COLUMN_PRODUCTNAME, product.getProductName());
    values.put(COLUMN_QUANTITY, product.getQuantity());

    SQLiteDatabase db = this.getWritableDatabase();

    db.insert(TABLE_PRODUCTS, null, values);
    db.close();
}

public Product findProduct(String productname) {
    String query = "Select * FROM " + TABLE_PRODUCTS + " WHERE " + COLUMN_PRODUCTNAME + " =  \"" + productname + "\"";

    SQLiteDatabase db = this.getWritableDatabase();

    Cursor cursor = db.rawQuery(query, null);

    Product product = new Product();

    if (cursor.moveToFirst()) {
        cursor.moveToFirst();
        product.setID(Integer.parseInt(cursor.getString(0)));
        product.setProductName(cursor.getString(1));
        product.setQuantity(Integer.parseInt(cursor.getString(2)));
        cursor.close();
    } else {
        product = null;
    }
    db.close();
    return product;
}
public boolean deleteProduct(String productname) {

    boolean result = false;

    String query = "DELETE FROM " + TABLE_PRODUCTS + " WHERE " + COLUMN_PRODUCTNAME + " =  \"" + productname + "\"";

    SQLiteDatabase db = this.getWritableDatabase();

    db.execSQL(query);
    db.close();
    return result;
}

}

And the product Class:

public class Product {

private int _id;
private String _productname;
private int _quantity;

public Product() {

}

public Product(int id, String productname, int quantity) {
    this._id = id;
    this._productname = productname;
    this._quantity = quantity;
}

public Product(String productname, int quantity) {
    this._productname = productname;
    this._quantity = quantity;
}

public void setID(int id) {
    this._id = id;
}

public int getID() {
    return this._id;
}

public void setProductName(String productname) {
    this._productname = productname;
}

public String getProductName() {
    return this._productname;
}

public void setQuantity(int quantity) {
    this._quantity = quantity;
}

public int getQuantity() {
    return this._quantity;
}

}

What was I doing BEFORE the bug?

1. I imported the Facebook sdk and ran the application a couple of times - it was fine
2. I changed the icon of the application and debug/AndroidManifest appeared, covered in red text saying: this is not allowed here, this is not allowed there. Ever since that the SQL is not working, although it was working perfectly fine

Thank you in advance!