1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/storage/public/mozIStorageAggregateFunction.idl Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,38 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsISupports.idl"
1.10 +
1.11 +interface mozIStorageConnection;
1.12 +interface mozIStorageValueArray;
1.13 +interface nsIArray;
1.14 +interface nsIVariant;
1.15 +
1.16 +/**
1.17 + * mozIStorageAggregateFunction represents aggregate SQL function.
1.18 + * Common examples of aggregate functions are SUM() and COUNT().
1.19 + *
1.20 + * An aggregate function calculates one result for a given set of data, where
1.21 + * a set of data is a group of tuples. There can be one group
1.22 + * per request or many of them, if GROUP BY clause is used or not.
1.23 + */
1.24 +[scriptable, uuid(763217b7-3123-11da-918d-000347412e16)]
1.25 +interface mozIStorageAggregateFunction : nsISupports {
1.26 + /**
1.27 + * onStep is called when next value should be passed to
1.28 + * a custom function.
1.29 + *
1.30 + * @param aFunctionArguments The arguments passed in to the function
1.31 + */
1.32 + void onStep(in mozIStorageValueArray aFunctionArguments);
1.33 +
1.34 + /**
1.35 + * Called when all tuples in a group have been processed and the engine
1.36 + * needs the aggregate function's value.
1.37 + *
1.38 + * @returns aggregate result as Variant.
1.39 + */
1.40 + nsIVariant onFinal();
1.41 +};
