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mozIStorageAggregateFunction

IID:763217b7-3123-11da-918d-000347412e16
Inherits From:nsISupports

MozIStorageAggregateFunction represents aggregate SQL function. Common examples of aggregate functions are SUM() and COUNT().

An aggregate function calculates one result for a given set of data, where a set of data is a group of tuples. There can be one group per request or many of them, if GROUP BY clause is used or not.

Methods

nsIVariant onFinal ( ) void onStep ( mozIStorageValueArray functionArguments )

nsIVariant onFinal ( )

Called when all tuples in a group have been processed and the engine needs the aggregate function's value.

void onStep ( mozIStorageValueArray functionArguments )

OnStep is called when next value should be passed to a custom function.

Arguments:
functionArguments: The arguments passed in to the function

References

This interface is passed as an argument to the following methods:

mozIStorageConnection.createAggregateFunction

Reference documentation is generated from Mozilla's source.