Tenía mi base de datos funcionando pero todos los registros que he insertado eran para fines de verificación, ahora quería eliminar todas las tablas y crear nuevas, así que intenté actualizar la base de datos cambiando la versión.

No cambié nada en las consultas de creación de tablas, pero recibo un error de restricción de clave externa (código 787).

Aquí está miDBHelper clase:

private static final String DATABASE_NAME = "roomatesDB";
    // database version
    private static final int DATABASE_VERSION = 3;

    // tables name
    public static final String APARTMENT_TABLE = "apartment";
    public static final String ROOMATE_TABLE = "roomate";
    public static final String SHOPCART_TABLE = "shopcart";
    public static final String ITEMS_TABLE = "items";

    // common column
    public static final String APARTMENT_NUMBER_COLUMN = "apartmentNum";

    // roomates table columns
    public static final String FIRST_NAME_COLUMN = "firstName";
    public static final String LAST_NAME_COLUMN = "lastName";
    public static final String PHONE_NUMBER_COLUMN = "phoneNumber";

    // shop cart table columns
    public static final String NUMBER_COLUMN = "number";
    public static final String LIST_NAME_COLUMN = "name";

    // item table
    public static final String PRICE_COLUMN = "price";
    public static final String ITEM_NAME_COLUMN = "name";

    // query for creating roomate table
    public static final String CREATE_ROOMATE_TABLE = "CREATE TABLE "
            + ROOMATE_TABLE + "(" + FIRST_NAME_COLUMN + " TEXT, "
            + LAST_NAME_COLUMN + " TEXT, " + PHONE_NUMBER_COLUMN + " TEXT, "
            + APARTMENT_NUMBER_COLUMN + " INTEGER, "
            + "FOREIGN KEY(" + APARTMENT_NUMBER_COLUMN + ") REFERENCES "
            + APARTMENT_TABLE + "(apartmentNum) " + ")";

    // query for crating shop cart table
    public static final String CREATE_SHOPLIST_TABLE = "CREATE TABLE "
            + SHOPCART_TABLE + "(" + NUMBER_COLUMN + " INTEGER PRIMARY KEY,"
            + LIST_NAME_COLUMN + " TEXT, "
            + APARTMENT_NUMBER_COLUMN + " INTEGER, "
            + "FOREIGN KEY(" + APARTMENT_NUMBER_COLUMN + ") REFERENCES "
            + APARTMENT_TABLE + "(apartmentNum) " + ")";

    // query for creating shop item table
    public static final String CREATE_SHOPITEM_TABLE = "CREATE TABLE "
            + ITEMS_TABLE + "(" + ITEM_NAME_COLUMN + " TEXT,"
            + PRICE_COLUMN + " DOUBLE, "
            + NUMBER_COLUMN + " INT, "
            + "FOREIGN KEY(" + NUMBER_COLUMN + ") REFERENCES "
            + SHOPCART_TABLE + "(number) " + ")";

    // query for creating apartment table
    public static final String CREATE_APARTMENT_TABLE = "CREATE TABLE "
            + APARTMENT_TABLE + "(" + APARTMENT_NUMBER_COLUMN + " INTEGER PRIMARY KEY"
            + ")";


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

    public void onConfigure(SQLiteDatabase db) {
        super.onConfigure(db);
        db.setForeignKeyConstraintsEnabled(true);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_APARTMENT_TABLE);
        db.execSQL(CREATE_ROOMATE_TABLE);
        db.execSQL(CREATE_SHOPLIST_TABLE);
        db.execSQL(CREATE_SHOPITEM_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + APARTMENT_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + ROOMATE_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + SHOPCART_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + ITEMS_TABLE);

        onCreate(db);

    }