26. Query for One Item Part Two

Here's the code for querying a single task:

    // Implement query to handle requests for data by URI
    @Override
    public Cursor query(@NonNull Uri uri, String[] projection, String selection,
                        String[] selectionArgs, String sortOrder) {

        // Get access to underlying database (read-only for query)
        final SQLiteDatabase db = mTaskDbHelper.getReadableDatabase();

        // Write URI match code
        // Write a query for the tasks directory and default case

        int match = sUriMatcher.match(uri);
        Cursor retCursor;

        switch (match) {
            // Query for the tasks directory
            case TASKS:
                retCursor =  db.query(TABLE_NAME,
                        projection,
                        selection,
                        selectionArgs,
                        null,
                        null,
                        sortOrder);
                break;

            // Add a case to query for a single row of data by ID
            // Use selections and selectionArgs to filter for that ID
            case TASK_WITH_ID:
                // Get the id from the URI
                String id = uri.getPathSegments().get(1);

                // Selection is the _ID column = ?, and the Selection args = the row ID from the URI
                String mSelection = "_id=?";
                String[] mSelectionArgs = new String[]{id};

                // Construct a query as you would normally, passing in the selection/args
                retCursor =  db.query(TABLE_NAME,
                        projection,
                        mSelection,
                        mSelectionArgs,
                        null,
                        null,
                        sortOrder);
                break;

            // Default exception
            default:
                throw new UnsupportedOperationException("Unknown uri: " + uri);
        }

        // Set a notification URI on the Cursor
        retCursor.setNotificationUri(getContext().getContentResolver(), uri);

        // Return the desired Cursor
        return retCursor;
    }