1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #include
"nsISupports.idl"
8 interface mozIStorageConnection
;
9 interface mozIStorageValueArray
;
14 * mozIStorageAggregateFunction represents aggregate SQL function.
15 * Common examples of aggregate functions are SUM() and COUNT().
17 * An aggregate function calculates one result for a given set of data, where
18 * a set of data is a group of tuples. There can be one group
19 * per request or many of them, if GROUP BY clause is used or not.
21 [scriptable
, uuid(763217b7
-3123-11da
-918d
-000347412e16
)]
22 interface mozIStorageAggregateFunction
: nsISupports
{
24 * onStep is called when next value should be passed to
27 * @param aFunctionArguments The arguments passed in to the function
29 void onStep
(in mozIStorageValueArray aFunctionArguments
);
32 * Called when all tuples in a group have been processed and the engine
33 * needs the aggregate function's value.
35 * @returns aggregate result as Variant.