This tutorial that shows notifyChange() call

Cursor setNotificationUri() method

Quiz Solution Explanation

Link to Solution Code

Previously, I already showed you setting up the notification uri and the insert method. Setting up the update and delete methods aren’t much different.

Setting Up the update Method

Since we actually update the pet information in updatePet() rather than update(), let's look there. I first check that something was actually updated by seeing the number of rows changed:

    // Perform the update on the database and get the number of rows affected
    int rowsUpdated = database.update(PetEntry.TABLE_NAME, values, selection, selectionArgs);

If it was more than zero, I call notifyChange:

    // If 1 or more rows were updated, then notify all listeners that the data at the
    // given URI has changed
    if (rowsUpdated != 0) {
        getContext().getContentResolver().notifyChange(uri, null);
    }

Lastly, updatePet() will return the number of rows that were updated.

    // Return the number of rows updated
    return rowsUpdated;

Setting Up the delete Method

The process is similar for delete. I first check that something was actually delete by seeing the number of rows changed:

    // Track the number of rows that were deleted
    int rowsDeleted;
    ...

// Delete all rows that match the selection and selection args
// For  case PETS:
rowsDeleted = database.delete(PetEntry.TABLE_NAME, selection, selectionArgs);

            ...

 // For case PET_ID:
 // Delete a single row given by the ID in the URI
 rowsDeleted = database.delete(PetEntry.TABLE_NAME, selection, selectionArgs);

If it was more than zero, I call notifyChange:

// If 1 or more rows were deleted, then notify all listeners that the data at the
    // given URI has changed
    if (rowsDeleted != 0) {
        getContext().getContentResolver().notifyChange(uri, null);

Lastly, delete() will return the number of rows that were delete:

    // Return the number of rows deleted
    return rowsDeleted;