Content Provider - Check columns for multiple tables

[Joan Zee]

I have two tables in my database. I've seen content provider examples for multiple tables but they only shows the CRUD code. So I'm not sure how to check columns for multiple tables.

I tried this

private void checkColumns(String[] projection) {

        if (Constants.COLUMNS != null) {
            HashSet<String> requestedColumns = new HashSet<String>(Arrays.asList(projection));
            HashSet<String> availableColumns = new HashSet<String>(Arrays.asList(Constants.COLUMNS));
            if (!availableColumns.containsAll(requestedColumns)) {
                throw new IllegalArgumentException("Unknown columns in projection");
            }
        }
        if (Constants.pCOLUMNS != null) {
            HashSet<String> requestedColumns = new HashSet<String>(Arrays.asList(projection));
            HashSet<String> availableColumns = new HashSet<String>(Arrays.asList(Constants.pCOLUMNS));
            if (!availableColumns.containsAll(requestedColumns)) {
                throw new IllegalArgumentException("Unknown columns in projection");
            }
        }
    }

Then did this in query

@Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
        checkColumns(Constants.COLUMNS);
        checkColumns(Constants.pCOLUMNS);
        queryBuilder.setTables(Constants.ITEM_TABLE);
        queryBuilder.setTables(Constants.PANTRY_TABLE);

        int type = URI_MATCHER.match(uri);
        switch (type) {
            case ITEMS:
                break;
            case ITEM:
                queryBuilder.appendWhere(Constants.COLUMN_iID + " = " + uri.getLastPathSegment());
                break;
            case sPANTRY:
                break;
            case PANTRY:
                queryBuilder.appendWhere(Constants.COLUMN_pID + " = " + uri.getLastPathSegment());
                break;
            default:
                throw new IllegalArgumentException("Unknown URI: " + uri);
        }
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        Cursor cursor = queryBuilder.query(db, projection, selection, selectionArgs, null, null, sortOrder);
        cursor.setNotificationUri(getContext().getContentResolver(), uri);
        return cursor;
    }

but I get this error

Caused by: java.lang.IllegalArgumentException: Unknown columns in projection

So how to check columns for multiple tables?