Calling onUpgrade() in SQLiteOpenHelper

Question

I know that this has been asked a million times. However, I do not find a way to call onUpgrade() within my subclass

I have an SQLite DataBase already built in a SQLite Manager which works properly. I would like the user to create an additional table within the app. So, as far as I have read, I have to do it in onUpgrade

Here is my code:

String DB_PATH =null;

private static String DB_NAME = "CompositionFoodTable_LatinAmerica";

private SQLiteDatabase myDataBase; 

private final Context myContext;

public FoodDataBaseHelper(Context context) {

    super(context, DB_NAME, null, 2); //Constructor with newer version
    //However I am not sure about this because when I run a query within the manager
    //to check the version, it throws 0
    this.myContext = context;
    DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
    // I am not calling getReadableDatabase() or getWriteable(). They destroy my
    //current version 

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    //NOT BEING CALLED
    // Drop older plates table if existed
    String CREATE_PRODUCT_TABLE = null;
    try {
        db.beginTransaction();
        for (int i = oldVersion + 1; i <= newVersion; i++) {


            CREATE_PRODUCT_TABLE = "CREATE TABLE IF NOT EXISTS PRODUCTS ( " +
                    "ID INTEGER PRIMARY KEY AUTOINCREMENT, " + 
                    "NAME TEXT, " + 
                    "DATE TEXT, " +
                    "SERVING_SIZE_G TEXT, " +

                    "H20_PERC TEXT, " +
                    "ENERGY_KCAL TEXT, " +
                    "PROTEIN_G TEXT, " + 
                    "TOTAL_FAT_G TEXT, " +

                    "CARBS_G TEXT, " +
                    "TOT_DIET_FIBER_G TEXT, " +
                    "ASH_G TEXT, " +
                    "CALCIUM_MG TEXT, " +

                    "PHOSPHORUS_MG TEXT, " +
                    "IRON_MG TEXT, " +
                    "THIAMINE_MG TEXT, " +
                    "RIBOFLAVIN_MG TEXT, " +

                    "NIACIN_MG TEXT, " +
                    "VIT_C_MG TEXT, " +
                    "VIT_A_EQUIV_RETINOL_MCG TEXT, " +
                    "MUFA_G TEXT, " +

                    "PUFA_G TEXT, " +
                    "SATURATED_FATTY_ACIDS_G TEXT, " +
                    "CHOLESTEROL_MG TEXT, " +
                    "POTASSIUM_MG TEXT, " +

                    "SODIUM_MG TEXT, " +
                    "ZINC_MG TEXT, " +
                    "MAGNESIUM_MG TEXT, " +
                    "VIT_B6_MG TEXT, " +

                    "VIT_B12_MCG TEXT, " +
                    "FOLIC_AC_MCG TEXT, " +
                    "FOLATE_EQUIV_FD_MCG TEXT, " +
                    "EDIBLE_FRACTION_PERC TEXT)";

            db.execSQL(CREATE_PRODUCT_TABLE);

            // create plates table
            db.setTransactionSuccessful();
        }
        } finally{

            db.endTransaction();
        }
            // Future schema changes has to go into this loop


}

Rest of my methods:

 /**
 * Creates a empty database on the system and rewrites it with your own database.
 * */
public void createDataBase() throws IOException{

    boolean dbExist = checkDataBase();

    if(dbExist){
        //do nothing - database already exist
    }else{

        //By calling this method and empty database will be created into the default system path
           //of your application so we are going to be able to overwrite that database with our database.
        this.getReadableDatabase();

        try {
            copyDataBase();

        } catch (IOException e) {

            throw new Error("Error copying database");

        }
    }

}

/**
 * Check if the database already exist to avoid re-copying the file each time you open the application.
 * @return true if it exists, false if it doesn't
 */
private boolean checkDataBase(){
    boolean checkdb = false;
    try{
        String myPath = myContext.getFilesDir().getAbsolutePath().replace("files", "databases")+File.separator + DB_NAME;
        File dbfile = new File(myPath);                
        checkdb = dbfile.exists();
    }
    catch(SQLiteException e){
        System.out.println("Database doesn't exist");
    }

    return checkdb;
}

/**
 * Copies your database from your local assets-folder to the just created empty database in the
 * system folder, from where it can be accessed and handled.
 * This is done by transferring bytestream.
 * */
private void copyDataBase() throws IOException{

    //Open your local db as the input stream
    InputStream myInput = myContext.getAssets().open(DB_NAME);

    // Path to the just created empty db
    String outFileName = DB_PATH + DB_NAME;

    //Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName);

    //transfer bytes from the inputfile to the outputfile
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
    }

    //Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close();

}

public void openDataBase() throws SQLException{

    //Open the database
    String myPath = DB_PATH + DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);

}

@Override
public synchronized void close() {

        if(myDataBase != null)
            myDataBase.close();

        super.close();

}

@Override
public void onCreate(SQLiteDatabase db) {
    // SQL statement to create plate table

}

Answer 1

However, I do not find a way to call onUpgrade() within my subclass

You don't call onUpgrade() yourself. SQLiteOpenHelper will call onUpgrade() if and when it is needed.

I have an SQLite DataBase already built in a SQLite Manager which works properly.

If you want to package a SQLite database with your app, please consider switching to SQLiteAssetHelper.

I would like the user to create an additional table within the app. So, as far as I have read, I have to do it in onUpgrade

No. onUpgrade() is for when the developer ships a new version of an app that requires a new database schema. It is not for tables, indexes, or anything else added on the fly based upon user input. For that, call execSQL() yourself, on SQLiteDatabase, at an appropriate point.